If you don't know how the page works, it's likely that you'll click off the site. Registration and pop-up windows can also kill your good feelings toward a site, Nielsen says. People don't trust sites to begin with and are skeptical even when providing information that could benefit them, he adds. At least if a site tells you it will use your information to send you targeted promotions, you can make an informed decision, Nielsen says. Sites can also gain trust through user ratings.
Good reviews receive positive recommendations from customers and push up to the top of the list.
Nielsen suggests that sites add a user-driven way to verify trustworthiness. No one understands what they mean.