Trust in Courier Services as a Determinant of Service Quality

The article aims to examine relationships between ve constructs: the usefulness of courier services (U), the ease of use of courier services (EU), the trust in courier services (T), the service quality (SQ), and the future intention to use courier services (FI).The research focuses on courier services. An electronic questionnaire was used to conduct condential interviews. It was distributed between January and March 2019. The number of questionnaires returned by courier service customers amounted to 1073. The authors used Generalized Least Squares (GLS) of Structural Equation Modelling (GLS-SEM) to verify the hypotheses. AMOS software was set to test the hypothesised relationships. The obtained results conrmed statistically signicant relationships between the variables of the ease of use and the trust in service, the usefulness and the trust in service, the trust in service and the service quality and, nally, the service quality and the future intention to use the services. The obtained results conrmed an important role of technological aspects in courier service quality, which will become the main determinant of the development of this sector in the future. The authors proposed a new approach to the denition of trust in service. Apart from the interpersonal trust, they shed more light on the trust in the supplier, i.e. the trust in the used technologies.


Introduction
The courier, express and parcel (CEP) market is booming around the world and particularly in developing countries. It is driven by the increasing Internet penetration and the popularity of online trade with growing middle-class population, prosperity and improved living standards. In 2019, compared to the previous year, the global CEP market value increased by 7.9%, reaching EUR 330.3 billion, while in terms of volume, it rose by 9.1% to 60.7 billion packages. According to the forecast, this growing trend will continue in subsequent years [1]. Currently, the European market share amounts to 22% of the global market value and 18% of the volume of shipments. The CEP sector in Europe is highly concentrated, as eight countries -Germany, Great Britain, France, Spain, Italy, the Netherlands, Belgium and Poland -generate 76% of the European GDP and 80% of the total revenues from courier service in Europe [2]. Compared to other European countries, the dynamics of the CEP market in Poland is one of the highest. In 2018, the courier operators handled 476 million parcels, which was 75% more than in 2014, while the market value increased by 60%, reaching PLN 6.95 billion. The growth rate of the Polish courier market is three times faster than the GPD in Poland. However, the share of the Polish CEP market amounted only to 3% of the European market value, and the volume of shipments was eight times smaller compared to Western countries, in particular Germany, Great Britain or France. In the near future, the growth of the courier market in Poland will be much faster than in other European countries, which places Poland among leaders, next to Holland and Romania, and con rms the potential of the Polish market [3]. In Poland, courier services evolved due to the implementation of modern technologies and the development of ecommerce, which resulted from better access to the Internet and the growing customer con dence in online shopping. This affected the structure of the client base, and B2C services have gradually become dominant in terms of the volume of shipments [4]. Under conditions of growing competition in the courier market driven by the development of e-commerce as well as increasing customer expectations, the improvement of the quality of courier services is one of the essential objectives for logistics companies [5][6][7] and a crucial factor in gaining competitiveness and success for online shops [8]. Furthermore, from the perspective of a client, the courier service is the most preferred form of parcel delivery affecting the opinion regarding an e-shop [9].
Customer perceived service quality is often used as a measurement to con rm business performance and market position, and it is acknowledged as one of the key factors of competitive advantage in the market [10]. The perceived service quality measures the level, to which a provided service matches customer expectations [11][12][13]. As a consequence, it affects customer loyalty [14,15]. Many research studies concern the identi cation of determinants of service quality in various sectors and branches. Among the most frequently cited contributions to the literature is a service quality model developed by Parasuraman, Zeithaml and Berry [16]. It presents mainly quality gaps during the preparation and provision of a service as well as ten following service quality determinants: reliability, responsiveness, competence, access, courtesy, communication, credibility, security, understanding and tangibles. The gap model was used as a basis for the SERVQUAL measuring scale of perceived service quality, which has a reduced number of service quality dimensions, namely, tangibles, responsiveness, reliability, empathy, and assurance. The scale was used to measure the perceived service quality of speci c products in different branches and, nally, has become the most popular and commonly used scale in the service sector [17]. Both the model and the scale indicate trust as an element comprising determinants of service quality perceived by clients. In the model, the credibility is related to trustworthiness, believability and honesty. While in the scale, the assurance means "knowledge, courtesy, and ability of employees to inspire trust and con dence towards the customers". In the context of the service sector, trust is de ned as the level of reliability guaranteed by the service provider to the receiver aiming to maintain and develop a positive relationship between them [18,19]. Trust in the service provider allows assessing the service or the provider before the consumption of a service. Despite changing conditions, customer trust means con dence that the service will be provided at an agreed appropriate level [20]. As a result, in the service sector, relationships between cooperating entities should be reinforced to eliminate the uncertainty of a client about expected bene ts (the received service quality) and to build trust in the service provider. If customer expectations are met or even exceeded by a seller, the customer trust increases and the relationship between these two entities can be strengthened [19].
The relationship between trust and quality of service is two-way. When customers have a better perception of service quality, they are more likely to trust the service. To increase the customer trust, a service provider should make an effort to reduce perceived uncertainties, uctuations, and risk during the service provision [21,22]. On the other hand, when customers trust solutions offered by a service provider, their assessment of the service quality is higher [20,23]. Finally, trust can affect corporate reputation [21] and build customer loyalty [22,23]. In the context of e-service, trust plays an important role in the provision of high-quality service as there is no direct (face-to-face) relationship between the parties. Examples of such a sector are e-commerce and m-commerce with courier services connected to both.
Unlike a traditional service, where it is possible to inspire trust using physical contacts, it is very di cult to establish a relationship with customers based on trust in cyberspace [25,26]. Trust plays a critical role in an e-commerce transaction because of the uncertainty and the risk involved [27]. Therefore, various researchers have identi ed trust as one of key service quality attributes considering the e-commerce speci city [8,26,[28][29][30]. Moreover, trust was stated to be the most important factor of e-customer satisfaction [31,32] and their repurchase intention [33][34][35][36].
Even though the courier service is the last and crucial link in online shopping, studies concerning the relationship between trust and service quality are limited. Most research on the courier service was focused on measuring the service quality or customer satisfaction using the SERVQUAL method slightly modi ed according to the speci city of the express/courier branch [37]. However, only some of them indicated trust as the factor of service quality. Yee and Daud proved that customer satisfaction was affected by assurance, which was connected with knowledge, courtesy of employees and the ability to inspire trust and con dence in customers [38]. Ho et al. found that overall customer satisfaction could be affected by trustworthiness and the quality of information, which would help customers in taking better decisions [39]. Micu et al. examined the quality of logistics service from the perspective of customers buying online. They outlined two dimensions considering the service quality, i.e., the operational service quality and the relational service quality. The relational service quality, which is focused on customer trust and con dence in the retailer's brand, appeared as the most important predictor for both the level of customer satisfaction and the level of customer loyalty [5]. Research conducted by Gulc con rmed that trust, among other factors, played an important role in the evaluation of the courier service quality [23].
Summing up, most previous research on the courier service quality did not consider the speci city of the courier service particular to the branch of e-commerce. Thanks to advanced IT tools and logistics solutions, the courier service is currently rendered to customers without direct face-to-face interaction, so it is gradually becoming based on self-service technology [4]. The development of technology-oriented courier service requires a different approach towards the de nition and measurement of trust in service in the context of the service quality and future intentions of customers. This study aims to ll these gaps. The article examines relationships between ve constructs: the usefulness of courier services (U), the ease of use courier services (EU), the trust in courier services (T), the service quality (SQ), and the future intention to use courier services (FI).
The article is structured as follows. The next part presents the results of a literature review indicating the role of trust in shaping service quality. A new approach to de ning the quality of services is proposed, considering the technological aspect of e-services and the need for consumers to rely on technological solutions. Next, a theoretical model of relations between the examined variables is presented, thus indicating the hypotheses for empirical veri cation. The next part of the article contains a description of the research methodology. In the section preceding the conclusions, the research results are presented and discussed in the context of other researcher outcomes.

Trust As A Determinant Of Service Quality -A Literature Review
Under the conditions of growing uncertainty in the business environment and the increasing role of risk, trust seems to be a key factor for interpersonal relationships, and it is also gaining more weight in manmachine, man-institution and man-product relationships.
A new promising research area includes the de nition of trust in service that is increasingly provided without direct contact between the service provider and the customer. Ben-Gal et al. con rmed that the success of service delivery is a multi-dimensional phenomenon [53]. The attempts to develop a de nition of trust in service were usually based on two approaches, i.e., performance-related (re ecting competence, customization, reliability, and promptness) and personality-related (emphasising empathy, politeness, and similarity) [54].
With the development of many categories of global services (e.g., retail banking, fast-food chains, and rental car agencies), it is di cult to build relationships based on trust [55]. With growing frequency, selfservice technologies replace direct contacts with the service provider. Trust in service is becoming particularly crucial in the case of limited access to information, incomplete information, and the increasing role of risk and uncertainty. The abstract nature of services will always remain the source of customer risk and uncertainty [54].
Examining the relationship between trust and future interactions among customers and nancial advisors, Johnson and Grayson focused on cognitive trust and affective trust, at the same time relating trust to interpersonal relationships [67]. Sekhon et al. developed a service trust model that included the overall trust and customer disposition to trust in service, leaving out the cognitive trust and affective trust [18].
A different approach to de ning trust in service was adopted by Ben-Gal et al. [53]. Referring to the model by Dietz & Den Hartog's [68], the authors treated trust as actions (actionable trust) resulting from previous beliefs and decisions [53]. Actionable trust has been de ned by the authors as the propensity for recommending a particular service to subsequent potential consumers. The conducted research con rmed that actionable trust was a dominant factor in the service success, thus called for the need to focus on the relational aspect of service encounters [53].
The development of e-services affects the importance of other factors [69]. The dynamic development of e-services (e-commerce and m-commerce) also requires building trust-based relationships that determine the quality of services. Following the traditional typology of trust (personal, institutional, and trust in technology), trust in service is a combination of trust in the institution itself (the service provider/vendor), interpersonal trust and the applied technologies.
The type of provided services and the character of relationships (direct or indirect) between the service provider and customer determine the process of creating trust-based relationships. In the case of direct contact of the customer with the service provide ( nancial insurance and advisory services), human and social factors play a more signi cant role in the process of trust-building. On the other hand, in the case where a service is provided in the form of e-services service provider trust and economy-based trust. Trust in the service provider was related to the safeguard of personal information and money, while the economy-based trust was more related to the functionality of the solution saving costs and time as well as the economic rationality [63].
Mcknight et al. investigated initial trust, i.e., trust in an unfamiliar web vendor, and developing and testing a Trust Building Model (TBM) [70]. Trust in the vendor was de ned as a multi-dimensional construct with two components, namely, trusting beliefs (perceptions of the competence, benevolence, and integrity of the vendor) and trusting intentions -the willingness to depend (a decision to make oneself vulnerable to the vendor). In their model, the authors proposed three factors for building consumer trust in the vendor: structural assurance (consumer perceptions of the safety of the web environment), perceived web vendor reputation, and perceived web site quality [70].
Research on human behavioural issues in relation to online services highlights the need to incorporate a trust variable that better explains the acceptance of electronic services by their users [71,72].
Despite the unquestionable importance of trust, the construct is conceptualized and measured very differently [55]. An overview of the de nitions of trust in service and measurement scales is given in Table  1.
Until now, the process of de ning and measuring trust in service has mainly focused on interpersonal relationships between the service provider (vendor) and the consumer. A different approach to trust must be developed for de ning and measuring service, having in mind two different types of services, i.e. human-oriented and technology-oriented, and with particular regard to the second group. The development of services with the help of ICT technologies (i.e., technology-oriented services), which replace interpersonal relationships, requires adopting a new approach to trust research, which also considers trust in material, physical factors. Many authors agree that trust does not only refer to interpersonal but also human relationships with technologies [65]. In many areas, relationships between customers and service providers are continuously replaced with various self-service technologies (e.g., in the banking industry) [76].
For example, the development of distance-learning technologies requires their users to have the skills to operate speci c software solutions and, thus, to rely on these technologies. Many researchers indicate that research of online transactions should also focus on two dimensions of trust: trust in transaction partners and trust in infrastructure (technology) [77,78]. When it comes to using services based on ICT in virtual environments, there are always two important players: the service provider and the technology, on which the service is based [74]. In the context of the development of electronic commerce, Ratnasingham stated that the virtual environment required trust to make it work. Technology alone is not enough [79]. According to Williams et al., trust in technology is a crucial determinant for the uptake of m-payment service by customers [61]. Trust in the government and the Internet were also the main factors contributing to citizen trust in e-government [80].
Courier service is the last and crucial step in the process of Internet shopping. More and more often, it is rendered to customers mainly using non-human interfaces based on information technologies and modern logistics solutions. The ICT tools used in courier service not only provide more convenience for consumers and business clients, but also offer more personalization options for online ordering, tracking, and payments [81]. Based on modern technologies, e-customer service provides current information to the customer about order processing and also enables order management and communication through the website or application of a logistics operator. The most advanced IT systems often integrate shipping companies to provide comprehensive service for the sender (manufacturer, seller) and support electronic order processing. Due to the increasing popularity of m-commerce, the courier operators offer special applications for clients and receivers to monitor the status of shipments and also change the place and time of delivery or even open a parcel locker [82,83]. Another solution based on information technology, which is crucial for parcel receivers in e-commerce, is Pick-up Drop-off network (PUDO), where customers can collect and return ordered products. The most used among these delivery solutions are pickup points in commercial centres and automated parcel lockers, which are more popular because of convenient location and access [84][85][86]. The use of arti cial intelligence by courier enterprises is becoming more frequent, especially seeking to contact customers through bots or chat-bots, which are gradually replacing traditional customer service. Experts predict that in the future, courier service will be provided without human assistance, thanks to arti cial intelligence, automatization systems and autonomous vehicle or drones [81,87].
Summing up, the rapid development of digitalization and modern technologies have been already transforming all transport and logistics segments, and it is expected to be the most impactful trend over the coming years, reshaping the entire courier branch. Therefore, the technology-oriented courier service supporting e-commerce branch requires a special research approach to customer trust in modern technologies and multicriterial approach [88]. Similar to the e-service and online shopping, trust in technologies should be examined as one of the key factors affecting the perceived service quality and future intentions of clients.
Considering the above, while building the model of factors that shape the quality of courier services, the authors focused on the technological aspects of the services. The starting point was the extension of the model of technology acceptance by the trust construct.

Ease of Use, Usefulness and Trust
In the case of courier services, the authors proposed to extend the existing scale for the measurement of trust in service by elements related to material and technological factors of the service process.
Many theoretical models have been developed to explain the processes involved in technology acceptance. In this approach, technology is de ned very broadly and often concerns the service itself. Davis, the founder of the commonly used Technology Acceptance Model (TAM), de ned the two main constructs in his model as follows: perceived usefulness is the degree to which the user is convinced that using a particular system/technology will improve the results/results of the work/activities. perceived ease of use is the degree to which the user is con dent that by using a particular system/technology he/she will be 'free' from physical and mental effort [89].
Trust is one of the important constructs determining the level of acceptance and technology use, which is often re ected in models. Belanche et al. recommended that researchers dealing with online service research should delve into TAM mechanisms, noting the positive and integrative effect of trust on adoption [90]. Other authors also added a new construct, such as trust, into the traditional Technology Acceptance Model [91,92]. Most studies consider the trust variable in technology acceptance models. On the one hand, they refer to trust as the factor determining the perceived usefulness and on the other hand, as a factor depending on the perceived ease of use.
Many researchers dealing with the factor in uencing trust in different categories of services have shown statistically signi cant relationships between the variables of the usefulness or the ease of use and the trust in service [90,[93][94][95].
Pavlou and Gefen analysed the impact of the variable of the ease of use and trust in technology and showed that the ease of use had a positive impact on the level of trust in technology [96]. Similar results were obtained by Klein, who focused on online communication systems between a doctor and a patient [97].
Chandra et al. noted that consumer trust was a signi cant determinant of perceived usefulness in mpayment due to the impersonal nature of the mobile Internet environment and the uncertainties involved in such transactions [74]. Although other authors, e.g. Mcknight et al. did not include the construct of usefulness in their Trust Building Model (TBM) and eventually adopted the perceived site quality construct, which re ects the usefulness of the proposed solutions based on the example of online advisory services [70]. By perceived site quality, the authors understand the technical performance of a website, the simplicity of its navigation and nding information, and the clarity of indications of how to contact or communicate with the service provider. Considering the above, the authors formulated the following two hypotheses: H1: The ease of use of courier services has a strong and positive in uence on trust in courier services.
H2: The usefulness of courier services has a strong and positive in uence on trust in courier services.

Trust and Service Quality
In terms of trust, service quality is an object of interest from various points of view, i.e., from the perspective of the quality of the service provider (which is a more human approach) and from the standpoint of the quality of solutions ensuring high quality of services provided (which is a more technological approach).
Wang et al. assumed that system quality was an important aspect of evaluating the system and examined the relationship between the quality of e-nancial services and trust in the services [59]. The authors proved that system quality, which demonstrated the professionalism and trustworthiness of the nancial service, promoted customer trust in the service. The authors positively veri ed the hypothesis that customer-perceived system quality was positively associated with their trust in the system. Similarly, Qureshi et al. proved that trust in the service provider was strongly dependent on the quality of the website offering e-commerce services [98]. Research conducted by McKnight et al. con rmed that site quality was a strong predictor of trust in the vendor [70].
Other authors also pointed out that technical factors shaping the quality of services played a greater role in ICT-based services without direct face-to-face contact between a buyer and a seller. Depending on the type of service, technological factors may relate to the quality of information, the appearance of the application or interface, and the security of information transfer. For example, Fung and Lee stated that the quality of site information and a good interface design increased consumer trust [99]. Research by Hsu et al. con rmed a statistically signi cant impact made by the trust in websites on the level of satisfaction with the use of websites and the quality of websites [100]. Weerakkody et al. researched user satisfaction with e-government services and proved that the quality of information and the system had a signi cant relationship with trust and user satisfaction [101]. Colesca empirically veri ed the hypothesis that perceived quality positively in uenced the trust in e-Government services [102]. The proposed model shows that better quality increases the trust of citizens in e-government services.
The authors of the study did not examine the initial trust but focused on the trust resulting from the previous experience of service consumers; therefore, they assumed that it might determine the service quality perceived by consumers. Thus, the authors proposed the following hypothesis: H3: The trust in courier services has a strong and positive in uence on perceived courier service quality.

Quality and Future Intention
Many authors have studied various aspects of the quality of provided services, e.g. the quality of websites, the quality of information, the quality of services and their impact on consumer intentions to purchase in the future.
Researchers of IT systems con rmed that factors related to the quality of systems played a role in their future use [103]. McKnight et al. examined two speci c trust-building levers: the website quality and the perceived reputation, and their in uence on initial purchase intentions. The authors veri ed a hypothesis regarding the perceived site quality having a positive relationship with the willingness to depend on a web vendor [70]. Qureshi at el. observed both direct and indirect relationships between perceived website quality and repurchase intention [98]. Therefore, in this study, the authors proposed the following hypothesis: H4: Perceived courier service quality has a strong and positive in uence on the future intention to use courier service.

Research Method And Measurement Data
The research focused on courier services. A survey was used to collect research data, which was done using the CAWI (Computer Assisted Web Interview) technique. Questionnaires were distributed to individual customers who had used courier services to order products via the Internet in the last three years. A link to the electronic research questionnaire was placed on the website of the Bialystok University of Technology and popular social media outlets.
Due to the lack of data on the number of persons using courier services in Poland, the general population was assumed to be the number of persons ordering or buying goods or services via the Internet for private use. In 2018, according to the Central Statistical O ce (GUS), the number amounted to 14 094 377 persons. The minimum sample size was 1067, assuming a con dence level of 0.95 (1-α) and a maximum permissible error of 3% calculated for the general population of about 14 million persons ordering or buying goods or services via the Internet. An electronic questionnaire was used to conduct con dential interviews; it was distributed between January and March 2019; 1073 questionnaires were lled and returned.

Measures
As many variables in the theoretical model are directly unobservable, a series of measures was used in each case. Based on the literature review, four items were identi ed to measure the usefulness of courier services (U), three -the ease of use of courier services (EU), and ve -the trust (T) in courier service. Service quality (SQ) and future intention (FI) to use were measured directly by using one item. For some constructs, the measurement variables were modi ed to highlight the more technical aspects that determine trust in service ( Table 2).
The constructs were measured using a seven-point Likert scale (1=totally disagree to 7=totally agree) or ve-point Likert scale in the case of Service Quality assessment (1 -very low service quality, 5 -very high service quality. Structural Equation Modelling (SEM) was used to verify the hypothesis. Alpha Cronbach's coe cients of the constructs were used to verify the reliability of the scale and proved the acceptable reliability of the scale ranging from 0.848 to 0.929 (Table 2). Descriptive statistics and composite reliability for the constructs and items are presented in Table 2.

Results And Discussion
To verify the hypotheses, the authors used Generalized Least Squares (GLS) of Structural Equation Modelling (GLS-SEM). AMOS software was set to test the hypothesised relationships shown in Fig. 2. GLS is a tool for estimating latent variables in a linear regression model. Source: elaborated by the authors.
The appropriateness of the measurement model was assessed using the Chi-Square statistics. According to Table 3, the χ2 value was statistically signi cant (χ2 = 321.84, p < 0.005) indicating the t between the model and the data. The use of other parameters also con rmed a good t of the model. The approximate ts were good, speci cally, the Normed Chi-Square (χ2/df) value = 5.191, RMSEA = 0.064, GFI = 0.958, AGFI = 0.929. Consequently, the model was likely to be interpreted as a real model of the relationship between the variables. The values obtained were at an acceptable level for this heuristic [113][114][115].
The positive veri cation of two hypotheses, H1 and H2, showed that the usefulness and the ease of use had a statistically signi cant in uence on trust in courier services. The diversi cation of regression coe cients indicated that the usefulness (U) had a greater impact on trust in courier service than the ease of use (EU). In the light of the obtained results, trust in courier service had a strong and positive in uence on courier service quality, which allowed the hypothesis H3 to be positively veri ed. The research results con rmed that the courier services quality had a strong and positive in uence on the intention to use courier services in the future and, thus, allowed to verify the hypothesis H4 positively ( Table 3).
The obtained results are consistent with conclusions reached by other authors. Other authors mainly analysed two variables taken from the model of technology acceptance, namely, the ease of use and the usefulness in the context of their relationship to trust. Pavlou and Gefen [96] and Klein [97] also con rmed a positive impact made by the variable of the ease of use on trust in technology in the case of communication services. Belanche at el. con rmed that in the case of online services, trust was affected by the perceived ease of use and directly affected the perceived usefulness [90]. The perceived trust, among other factors, was identi ed by Hampshire as a key predictor of the perceived usefulness of mobile payment systems [116]. In the adopted model, trust in service was understood as a construct having a more technological character, so the questions were focused on technological solutions offered by a courier service provider. For this reason, it was also assumed that the two key variables taken from the original TAM model (i.e., the ease of use and the usefulness) would determine the trust in service. The obtained results con rmed that both variables -the ease of use and the usefulness -had a statistically signi cant impact on trust in courier services, thus allowing for the veri cation of hypotheses H1 and H2.
However, comparing the factor loadings for both variables, it was clear that the usefulness variable had a stronger impact on trust in service.
In this study, trust was treated as a determinant of service quality similarly to other research [21,117]. The difference in the model assumption resulted from the fact that most other researchers treated trust in service as an interpersonal trust or institutional trust in the service provider. However, a more technologyoriented de nition of trust (trust in service, meaning trust in technology offered by a service provider) meant that trust could be a determinant of service quality. The achieved results allowed the hypothesis H3 to be positively veri ed, which re ected the relationship between trust in courier services and the perceived courier service quality.
Positive veri cation of hypothesis H4 indicating a statistically signi cant impact of the perceived courier service quality on the future intention to use courier service is consistent with the results of other researchers dealing with service quality issues [34].

Conclusions
Growing competition in the eld of courier services and the dynamic development of e-commerce and m-commerce drive further improvement of service quality and the search for new innovative operational and technological solutions. The success of a courier company also depends on organisational, social and technological factors. Soon, we should expect further digitalization of logistics processes with the help of modern technologies, such as the Internet of Things and Big Data Analysis. Also, the provision of logistics services will be supported by robotics, automation and self-learning systems. The success of courier services will, therefore, depend on the acceptance of new technological solutions by their users.
This research aimed to determine the impact made on trust in courier services and their quality by two basic variables taken from the model of technology acceptance. The authors proposed a new approach to the de nition of trust in service that focused on trust in the supplier or trust in the used technologies additionally to the interpersonal trust.
The obtained results con rmed statistically signi cant relationships between the variables or the ease of use and trust in service, the usefulness and trust in service, trust in service and the service quality, and, nally, the service quality and the future intention to use the service.
Even though the research generated new knowledge, it had limitations. First, the future intentions to use courier services were a dependent variable in the adopted theoretical model. Although the intentions are important, many authors pointed out the need to consider the current state of the use of services while devising models. In the proposed model, the quality of courier services was evaluated directly using a subjective assessment of the service quality. The datasets used and analysed during the current study are available from the corresponding author on reasonable request.

Competing interests
The authors declare that they have no competing interests.

Funding
The study was a part of the Research Project No. 2017/25/N/HS4/02051, Relational model of quality shaping system of courier services in e-commerce funded by the National Science Centre, Poland.

Authors' contributions
The authors equally contributed to the elaboration of this study. All authors read and approved the nal manuscript. structural assurance (i.e., consumer perceptions of the safety of the web environment), the perceived web vendor reputation, and the perceived website quality [70] The structural assurance of the web: · The Internet has enough safeguards to make me feel comfortable using it to transact personal business.

·
Legal and technological structures adequately protect me from problems on the Internet.
· I feel con dent that encryption and other technological advances on the Internet make it safe for me to do business.

·
In general, the Internet is now a robust and safe environment for business.     Measurement model.