Rational Choice Theory RCT is used by some scholars in disciplines such as modern political science, microeconomics, sociology and philosophy. If you had studied about that, You would know already. Let's see 4 cases about ITAKI case 1) I've been correcting a notebook entry of others. Users of ITAKI have been correcting a notebook entry of others So my notebook entry have been corrected whenever I wrote case 2) I've never corrected a notebook entry of others , Users of ITAKI have been correcting a notebook entry of others So my notebook entry have been corrected whenever I wrote case 3) I've been correcting a notebook entry of others , Users of ITAKI have never corrected a notebook entry of others So my notebook entry have never corrected case 4) I've never corrected a notebook entry of others , Users of ITAKI have never corrected a notebook entry of others So my notebook entry have never corrected What's the happiest case for you? maybe the case 2 ? right? Yes. it's the happiest case for you. . . . But you have to know that you're not the only person who thinks like that. So actually the selfishness of users result in the Case 4. This is RCT. that's why it's not easy to get friends from ITAKI Just for fun.. :)