Online ad spending predicted to make double digit annual gains through 2009.

eMarketer estimates that online advertising will make up 4.6 percent of total media advertising spending this year, and projects that the share will rise to 7.5 percent by 2009. Online ad spending is expected to jump 33.7 percent this year to total $12.9 billion. Growth will cool going forward, but remain in the double digits through 2009.

 
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