NBC Universal has announced that it plans to limit the length of pre-roll advertising (ads displayed before you get any content) in short Internet videos to 15 seconds or less. NBC’s move appears to be part of a trend towards shorter, more targeted advertising in Internet video.

Unfortunately, it looks like MTV is bucking this trend. Its video podcasts are almost 50% advertising, a problem that could not only limit interest in their content, but could even damage their brand among influential technology first adopters.

The MTV News video podcast is unusually heavy on advertising and unusually light on real content. Here’s a breakdown of a typical episode (MP4):

• 3 seconds of MTV Podcasts branding
• 19 seconds of advertising for Clean & Clear
• 4 seconds of MTV News branding
• 47 seconds of content
• 4 seconds more of MTV News branding
• 10 seconds more of MTV Podcasts branding

All in all, it’s 40 seconds of advertising in a video podcast that’s not even a minute and a half long.

By comparison, an episode of the wildly popular indie video podcast Ask A Ninja has about 10 seconds of advertising within a three minute plus video podcast, followed by a post-roll ad. That’s about a tenth as much advertising, by percent, as MTV’s video podcast, and it’s much less intrusive.

MTV appears to be trading on its brand in order to sell ad space. While this may offer short term gain, it could prove damaging both MTV’s brand and the brands of its advertisers among a crucial demographic – the young, influential first-adopting information omnivores that make up a large part of the video podcast audience.