Customers sometimes visit Internet stores just for fun, without strong intentions to purchase a product (hereafter "to browse"), and they sometimes visit with strong intentions to purchase a product (hereafter "to purchase"). Our research question is whether or not customers respond to the same interface features in a different manner depending on their purpose of visit (e.g., to browse or to purchase). We believe that this is an important question for Internet stores. If Internet stores can predict different influence of a certain web interface feature on customers who have strong purchase intentions from the store, then they can design Web shopping sites to serve those customers more effectively. For example, assuming that those customers who visit to purchase usually conduct checkout processes, while those who visit to browse are less likely to conduct checkout processes, it would be effective to include the Web interface features that are especially effective for those who visit to purchase in the checkout screens. This study will investigate whether or not customers' purpose of visit (e.g., to purchase or to browse) moderates the impact of portal affiliation and a store's self-proclaimed assurance on customer trust. A laboratory experiment is designed to investigate whether or not customers who have a different purpose of visit respond to portal affiliation and self-proclaimed assurance in a different manner.