>But it is though? At some point quantitative change achieves a qualitative effect. I would think Facebook or LinkedIn or Twitter have all reached that qualita

>But it is though? At some point quantitative change achieves a qualitative effect. I would think Facebook or LinkedIn or Twitter have all reached that qualitative effect to change from being just a discussion forum. However qualitatively the social functions of these apps present an extra functionality missing from traditional discussion forums. Being able to track users, notifications of the users updates, blocking certain users from being in the message - which is a traditional messaging function not found in discussion forums. Suggestions of people or subjects to follow given on what you have done in the past, weighted based on various algorithms to determine how recent your past activity was and what your current interests seem to be.. I'm sure you could think of a load of other functions that are not traditional discussion forum functionalities.