In Depth Scores Sliver of Ad Revenue earned only $5.75 million in online video advertising revenue, according to estimates released today by eMarketer.

The new-media research firm issued the projection based on video streams delivered on the site during the 2008 Beijing Olympics. eMarketer said the figure represents only 1.1% of this year’s projected $505 million in online video ad spending.

Although drew record traffic, most of the visitors were not viewing videos, eMarketer said. That’s because visitors had to download Microsoft Silverlight technology to view videos, an additional step that turned off many visitors, the firm said.

NBC said its site had delivered nearly 65 million video streams and 1.3 billion page views by August 21 and that the Games are on track to be the most viewed Olympics ever. NBC also sold more than $1 billion in ads for the Games and an additional $25 million since the competition began.

Updated with NBC comment at 5 p.m.