As the Internet continues to expand beyond comprehension, ad revenues are growing by the billions, according to the Interactive Advertising Bureau's (IAB) 2011 Internet Advertising Revenue Report. What do you think Internet ad revenues reveal about the growth of the Internet? Share your thoughts below.  Internet advertising revenues reached $31 billion, with 22 percent more than the 2010 revenues of $26 billion, the report found. Behind this unprecedented revenue growth lies some important highlights. Mobile advertising became a major source of advertising revenue (with $1.6 billion revenue). Search ad revenues topped all ad revenues at $14.8 billion and display-related advertising had $11.1 billion in revenues. The good news for spam haters is that email ad revenues were at the bottom at $213 million. If you're a website owner, share with us the budget you invested in ads during 2011. Randall Rothenberg, the President and CEO of IAB said:

This historic moment, with an especially impressive achievement in mobile, is indicative of an increased awareness from advertisers that they need to reach consumers where they are spending their time--in digital media. Pushing past the $30 billion barrier, the interactive advertising industry confirms its central place in media. Across search, display, digital video, digital provides a wealth of opportunity for brands and consumers. With the proliferation of smartphones and tablets, it is likely that the tremendous growth in mobile will continue as these screens become even more crucial to the marketing mix.