Each day as we surf the Web, we're confronted by the presence of the ads. Whether we see them in Flash, video or other formats, our eyes are saturated. So how much money can online advertising generate? The Interactive Advertising Bureau says it's a lot. The group reports that in the first half of 2011, Internet ad revenues were close to $15 Billion. IAB says more than 500 media and technology companies are responsible for selling 86 percent of the advertising in the U.S. During the same period of 2010, online ad revenues amounted to $12 Billion. It seems the online world hasn't been hit too hard by the global recession, since every year ad growth has grown (23.2 percent over 2010 and 11.3 percent over 2009). So far this year search ads earned almost 49 percent of the total, hitting $7.3 billion. Display ads (banners, videos, rich media, sponsorships) accounted for percent, classfields were 8 percent, referrals accounted for 5 percent, and e-mail ads had 1 percent. Said Randall Rothenberg, IAB's president and CEO:

The remarkably resilient performance of interactive advertising so far in 2011 demonstrates that more marketers are placing big bets on digital to tell their brand stories. This welcome news, in light of the weakness in a large part of the rest of the U.S. economy, confirms that the innovations happening in interactive marketing deliver great value to the industry and to the consumer.

IAB says that the results were gathered directly from companies that sell advertising on the Internet. The data includes "online advertising revenues from Web sites, commercial online services, free e-mail providers, and all other companies selling online advertising."