New York-based FullTurn Media, maker of racy sex-ed videos under the illumistream brand, was once one of YouTube's (GOOG) most-watched producers. Now it's struggling to get a tenth of its traffic on the site.

Earlier this summer, the company was flying high -- averaging a million views a day. But that ended in June when, in one fell swoop, YouTube classified most of its popular videos as "adult" -- which requires YouTube viewers to register to watch them. It also took the videos out of contention for advertising spots in YouTube's partner program, and removed them from all of YouTube's leaderboards.

Why? FullTurn's videos address sexual health themes with porn-like images and production values, and used to dominate YouTube's leaderboard with suggestive thumbnails and click-friendly titles such as "Get Friendly With the G-Spot, " "Handling Too Much Man," and "Micropenis." (The videos are available in original form on one of the company's sites, sexhealthguru.com.)

YouTube's forcing people to register to watch FullTurn's videos reduced their video views from a million a day to about 100,000. Before the removals, YouTube accounted for 80% of FullTurn's video views and 20% of revenue.

YouTube's move appears to have been part of a broader crackdown on partner videos deemed advertising-unfriendly. YouTube, of course, is under pressure to increase ad revenue. At the same time, it is also by far the biggest venue for online video, and any small change causes major tremors in the small but growing Web economy of Web video.

The company didn't respond to a query about its standards for partner videos. Other producers that spent time in YouTube's penalty box included FordModels, SportsIllustratedSwimwear, and NoGoodTV.

Technically, FullTurn was suspended from YouTube for "thumbnail gaming," or using images for video that don't accurately reflect the content. It's a practice that annoys some YouTube partners, and can litter the leaderboards with deceptive videos. Among the offending thumbnails: a woman suggestively eating a
banana on a video about nutrition, and a picture of two turtles in flagrante for a video about pheromones.

In its attempts to earn its way back into YouTube's good graces, FullTurn has gone through and re-edited its catalog. But while suspension from YouTube is quick, getting reinstated can be an arduous, opaque process. Producers complain there are no clear definitions of what crosses the line or specific standards. Instead, YouTube has a committee that reviews each case and can accept or reject videos for any reason.

See Also:
YouTube Payola: Is Anyone Paying For Views?
Experts Agree: YouTube Dominates. But By How Much?
YouTube Finally Figures Out How To Make Money: Big Ads On Its Homepage
YouTube Exec: We're Selling Advertising Against 'Less Than 3%' Of Our Videos