The trouble with social networking... (see The Social Brain Hypothesis, page 184, column 3)
British anthropologist Robin Dunbar [...] noted in 1992 that humans—like other primates—can handle only 150 relationships. If we try to add many more connections, our little brains get overloaded.
The conclusion from a ballpark example...
Thus Twitter has a real value of $12.26 per user. Compare that with Facebook, which has a perceived value of $300 a user—or at least it did last year, when Microsoft purchased its 1.6% stake for $240 million and the site had 50 million users.
Even with this example, there is the difficulty of inserting the ads... In messages? On the front end interface?