This study by the VTT – Technical Research Centre of Finland may be useful for you.
Their summary is:
“Social media is becoming more and more attractive to Web users. However, the majority of social media services do not have a clear business model. Typically an innovative idea gives birth to a service, which people can use free of charge. The most common way to create revenue is via advertisements: Google ads appear in many services. In the long run, however, social media has to adopt alternative means for making money.
At the moment there are a few alternative business models, of which four larger themes are reported: Crowd-sourcing, revenue sharing between services and users, developing and selling underlying technologies, and adopting social media tools and approaches for professional use. Some examples of these approaches already exist.
The report also identifies and defines some core concepts of social media, as well as investigates various phenomena co-occurring with social media, namely user activeness, identity, copyrights, mobility, trust, and side-effects. These phenomena should be kept in mind when designing and launching social media products and services.”
The full report is: (pdf) HERE
Any comments welcome and I shall try to add to it