Online advertising revenues reached almost $5.9 billion in the third quarter, an 11 percent increase for the same period last year, according to the Interactive Advertising Bureau.

The third quarter numbers increased the yearly revenue total to $17.3 billion, up from $15.2 billion at this point in 2007. But while year-over-year growth is strong, the numbers grew very little between the second and third quarters this year. According to the IAB, the third quarter numbers were only 2 percent higher than those from Q2, and the drop off in growth is a result of the poor economy.

"A weakening economy will continue to be a challenge to all forms of advertising-supported media," said David Silverman of PricewaterhouseCoopers LLP, who released the numbers in conjunction with the IAB. "However, the internet should be better poised to withstand the storm given its ability to combine performance-based advertising along with broad-based branding."

Recent studies seem to support Silverman's claim. The Advertiser Optimism Report by Advertiser Perceptions found that 68 percent of marketers plan to increase their spending online in the next six months, according to Advertising Age.

The outlook for traditional media remains bleak. Only 14 percent of marketers plan on increasing their spending on broadcast television, while a measly 9 percent will put more money into newspapers. The confidence in interactive comes largely from the ability to easily track and monitor the results. According to the Optimism Report, 83 percent of marketers making online decisions feel ad results are more important than cost or price.

"We're seeing less slowing in media that's more accountable and targetable," said Randy Cohen, principal at Advertiser Perceptions. "We still see less optimism for online and for cable TV, but it's more severe in the media that tends to be less accountable."