The Interactive Advertising Bureau is reporting that third quarter revenues from internet advertising are up 22% this year over the third quarter of last year. Revenues have climbed to $7.9 billion in the eighth consecutive quarter of year-to-year growth.

President of the IAB Randall Rothenberg attributes the staggering growth – which also represents a rise of 2.7% over the second quarter of 2011 – to an increasing awareness among advertisers of the importance of digital advertising space. The following chart shows the steady rise of internet ad revenues over the past eleven years:

In addition to the increasing awareness among advertisers cited by Rothenberg, it seems likely that the increasing use of mobile devices, namely phones and tablets, in web traffic plays a role as well. This would account for the sharper rise in revenues beginning near the end of 2009. What is perhaps most surprising, though, is that even in the difficult economic climate of the past few years, ad revenues have consistently grown by leaps and bounds.

Founded in 1996, the IAB is a group of media and technology companies that together sell over 85% of the advertising space on the internet. The organization began collecting and publishing revenue data in 1999, and its reports are widely regarded as the most accurate gauge of internet advertising revenue.