An eMarketer.com report estimates that Google will account for twenty-five percent of all online ad revenue. Google's share continues to increase (65% increase YoY) while Yahoo's growth continues to decrease, eMarketer says. Google first surpassed Yahoo in ad revenue back in 2005, but barely. Google in 2006 is expected to earn over $4 billion in ad revenue but Yahoo has just $2.9 billion according to eMarketer.com.

Now consider this Today US online advertising is worth 13 Billion $ and is expected to go to 26 Billion $ by 2013, imagine the power of Google!.

Source: Search Engine blog and Red Herring