Internet television advertising revenue will hit $10 billion worldwide by 2011, according to an August 2007 Understanding & Solutions press release.
That would equal 18% of all Internet advertising that year, which the firm forecast at $57 billion.
Understanding & Solutions also stated that the amount of video on the Internet is doubling each year.
"Globally, we estimate there are more than 20 billion videos being streamed across the Web each and every month," John Bird, principal consultant with Understanding & Solutions, said in a statement. "In the US alone, active Internet video users are streaming an average of 55 videos per month — and this is just the beginning."
Alison Casey, business director for Understanding & Solutions, noted that problems will accompany the growth.
"The national boundaries which govern broadcasting today will also be challenged by the global nature of the Internet, as has been the case with e-commerce," she said in the statement.
Most Internet TV content will be free to users over the next one or two years. Viewing will take place mainly on PCs and handheld devices. Early adopters are already networking Internet TV to their main TV screens.
But it will be another three years before the technology is widely accepted as a conventional system for delivering content to the living room.
iSuppli estimated worldwide online TV revenues for 2011 at $5.8 billion.
Internet protocol TV (IPTV) has only just emerged in the US and is unlikely to challenge other TV distribution platforms, according to Kagan Research.
Get an in-depth look at social network ad spending. Please read the eMarketer US TV Trends: The Impact of DVRs, VOD and the Web report.