Online ad spending is set to grow almost 14 percent, from $45.6 billion, in 2010, to $51.9 billion, in 2011, according to a new forecast from Borrell Associates.

By next year, local online advertising should grow by almost 18%, from $13.7 billion, in 2010, to $16.1 billion, in 2011.

Almost 20 percent of advertising on social networks comes from local businesses and marketers, according to a new report from Borrell Associates.

Borrell says that going into the research the firm assumed that ads on social networks were almost all national.  The amount of local advertising forecast to be spent in 2009 comes to $641 million out of $3.26 billion across 118 social networking sites.

Local online advertising should deliver an eleven-figure payday to site publishers, according to a forecast from Borrell Associates.