Advisory services company BIA/Kelsey predicts ad revenues for social media sites will quadruple between 2010 and 2015, rising to £5.2 billion.

This prediction has been made by analysts in BIA/Kelsey’s U.S. Local Media Annual Forecast (2010 – 2015). According to them, social media ad spend is any money that is spent on advertising through the various social networks, but does not include virtual goods, rewards, social gaming etc.

At present the major source of advertising on these social networks is display advertising, which generated £1.3 billion in 2010 and is expected to generate £4.8 billion in 2015. However other sources of advertising such as ‘promoted tweets’ on Twitter which currently generate negligible income are likely to become popular by then and will generate £375 million.

The compound annual growth rate in the social media arena will be more than 30%. At present of course the major amount of all the revenue is going to Facebook which is the most popular social network and currently has more display ad impressions than both Yahoo! and Google.