We decide what to do in a situation by looking to what others are doing. If many individuals have decided in favor of a particular idea, we are more likely to follow, because we perceive the idea to be more correct, more valid. Show how popular your site is by displaying your subscribers and unique visitors. 100,000 people can't be wrong. Liking People prefer to say yes to those they like.
People tend to believe what friends say over strangers.
Dr. Cialdini found that American Heart Association donations nearly doubled when good looking fundraisers came a-knocking. Show your users how much other users like your site. Authority People believe symbols of authority. Uniforms, credentials, and experience all give the appearance of authority, which people tend to believe. Show the expertise of your writers, say that you are the authority on your subject, and back it up with awards and glowing user comments.