Internet TV is growing at an insane rate. According to comScore, U.S. Internet users viewed more than 12 billion online videos during the month, up 45 percent versus year ago.

Nearly 142 million U.S. Internet users watched an average of 85 videos per viewer in May.

Google Sites (mainly YouTube) attracted the most viewers (83.8 million), who watched an average of 50 videos per person. Fox Interactive attracted the second most viewers (60.8 million), followed by Yahoo! Sites (40.2 million) and Microsoft Sites (29.5 million).

Other highlights:

• 74 percent of the total U.S. Internet audience viewed online video.
• The average online video viewer watched 228 minutes of video.
• 82.2 million viewers watched 4.1 billion videos on YouTube.com (50.4 videos per viewer).
• 54.8 million viewers watched 703 million videos on MySpace.com (12.8 videos per viewer).
• 6.8 million viewers watched 88 million videos on Hulu.com (13.0 videos per viewer).
• The duration of the average online video was 2.7 minutes.

For several years, we’ve been saying that Internet TV was going to make traditional TV’s shift to digital irrelevant:

“US broadcast television is scheduled to go digital on February 17, 2009, by order of the Federal Communications Commission. Broadcast television’s move to digital could be the start of something big.

But with Internet broadcast audiences in the millions, video download audiences in the tens of millions, and portable devices like the iPhone making Internet video increasingly available, it’s starting to look the broadcast television’s switch to digital may be traditional television’s last hurrah.”

It’s looking more and more like 2009 will be the year this will happen, at least for first movers.

Broadband users are already abandoning television for Internet TV. By this time next year, there will be a broad range of Internet TV devices available, including the XBox 360, Apple TV, Roku’s Player and Kodak’s Theater HD Player. That, plus more content, will only accellerate this shift.

Here’s the rest of the info from comScore’s announcement:

Fox Interactive Media Increases Market Share

In May, Google Sites once again ranked as the top U.S. video property with 4.2 billion videos viewed (representing a 35 percent share of all videos viewed), with YouTube.com accounting for more than 98 percent of all videos viewed at the property. Fox Interactive Media ranked second with 778 million videos (6.4 percent), gaining 1.3 share points versus April. Yahoo! Sites ranked third with 347 million (2.9 percent), followed by Microsoft Sites with 246 million (2.0 percent). Hulu.com, a joint venture of NBC and Fox featuring full-length broadcast TV programs, debuted in the tenth position with 88 million videos being viewed (0.7 percent).

*Rankings based on video content sites; excludes video server networks.  Online video includes both streaming and progressive download video.

*Rankings based on video content sites; excludes video server networks.  Online video includes both streaming and progressive download video.

Image: Alexandre Van de Sande