Choosing Social Network Models

From Wharton:  An extensive piece on the topic.  " ... Recent downturns in the stock price of several social media companies -- several of which debuted to much fanfare -- may be due, in part, to investor worry over whether these firms are successfully monetizing their services. Social media is a relatively new concept, and business models are still being fleshed out, experts note, adding that Facebook, Groupon, LinkedIn, Zynga and others must find ways to make money without alienating their most valuable assets -- users. .... "