The catch? You already know about it. It’s “Protail video”–i.e, short clips made by people other than kids in their bedrooms. Like “Dr. Horrible,” the mini video series created by Joss “Buffy The Vampire Slayer” Whedon. The stuff that we’ve been hearing advertisers like, for quite some time.

Oh. Wait. There’s another catch. That 600 percent growth will bring the market to a grand total of…$75 million this year, worldwide.

It’s paltry numbers like these that explain why Google’s (GOOG) YouTube was predicting 2008 sales of $200 million–and that was the number the company was floating this summer, before the ad market started plummeting.

OK. Back to good news. Gartner figures that sometime in the future, this market really does take off: It thinks protail will generate $1.5 billion by 2012. I will do my part by using my newly purchased Flip video camera (though not the HD model, which no one bothered to tell me about before I shelled out for my Mino) to generate some compelling and ad-friendly video content ASAP.