There are many explanations about real life vs online:<p>1. In RL you're a peer and assigning someone a rating you are attempting to establish your dominant position where none existed before. A web site is not a peer so the idea of ceding authority to it is less outrageous.<p>2. Website is a game. This induces an age regression - people feel like children who get scores assigned to them (their work) and get their worthiness judged based on those scores. To that end it helps to make things fun, easy, brightly colored, with large letters and not too much time commitment.<p>3. There is a "suspension of disbelief" going on there to help with #2 - like in a movie.<p>4. Web site has already assigned judgment to someone people perceive as their peers. Thus peer's acceptance of such judgment creates social proof of authority.<p>5. For some reason people discount opinion of a single, known peer after some time taking it as a given, and then seek validation from strangers.<p>6. Web site has an oracle-like property to it - it knows things about you. This goes deeper into horoscopes and stuff. You could pull it off yourself it you bothered to learn horoscoping techniques - basically telling people what they want to hear about themselves.