Social media reaching a plateau?

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Friendster. Myspace. Facebook. LinkedIn. Most likely, you belong to at least one of these (three for me).

The whole social media/social networking frenzy started with Friendster in 2002. Eventually, several eUniverse employees realized the potential of Friendster and developed Myspace. Now, the social media king (based on its Alexa ranking), Myspace is more than 100 million members strong and averaging an additional 230,000 new signups each day, proving the whole social media is continuing to expand.

Even with the industry expanding, could social media be reaching a revenue plateau? Or is there even such a thing as…