Advertisers will spend over £100m pushing their brands on UK social networks this year.
According to eMarketer, ad spend will grow by 76.9% from £65m in 2007 to £115m by the end of this year.
It predicts this figure will increase to £285m by 2012, driven by take-up of ad formats like integrated promotions and sponsored groups or pages within social networks.
However, the figures are dwarfed by ad spend on social networks in the US. The ad spend on MySpace US alone is forecast to hit $755m (£394m) in 2008, which is more than treble the total for all UK social networks.
Debra Williamson, senior analyst at eMarketer, said, "Although social networks have been a part of the UK online landscape for several years, most have only just started their ad sales efforts. Facebook didn't have a UK sales office until late 2007 and MySpace and Bebo have taken their time to ramp up their sales efforts.
"Another factor is the high dependency on search advertising in the UK. We estimate search will make up 60% of total online ad spend in the UK this year, compared with 40% in the US. That leaves less money for social networks," she added.
The eMarketer forecasts include general social networks, networks linked to portals, niche networks and marketer-sponsored social networks.