All web designers use perceptual persuasion in their designs, but without knowing they do. Interaction designer Wouter Middendorf delves into the matter:
“Persuasive design is hot. Especially on the web as designers found out that the internet perfectly lends itself for persuasion. The combination of both interpersonal and mass communication as well as its interactivity creates a perfect environment to apply persuasive techniques like the ones described by Maurits Kaptijn in his article on Persuasion Profiling. These kind of persuasive techniques can be traced back to psychological principles that rely on symbolic strategies to trigger emotions or emotional aspects in order to motivate people towards a preferred behavior. Almost all of these techniques work on the level where users interact with the website. A good example of such a persuasive technique on that interaction level can be found on LinkedIn. Users are persuaded (or motivated) to complete their profile through the completeness bar that is placed next to their LinkedIn profile. The psychological principle that is at work here is the fact that people crave for completion, which is why it works so well.