Facebook drives US social networks ad spending with over $3 Bn in 2011

US marketers will spend $3.08 billion to advertise on social networking sites this year, eMarketer predicts.

Spending will be up 55% over the $1.99 billion advertisers devoted to social networks in 2010 and will rise by a further 27.7% next year to reach nearly $4 billion.

This year’s dramatic growth in spending will bring social media ad dollars to 10.8% of the total spent online in the US. Worldwide, where social network ad spending will rise 71.6% to $5.97 billion, that proportion will be somewhat lower, at 8.7%.

eMarketer predicts ad spending on the world’s top social network will reach $2.19 billion in the US this year and just over $4 billion worldwide—both more than double last year’s figure.