We may never know if YouTube has what it takes to become a high-margin trophy on Google's (NASDAQ:GOOG) mantelpiece, but some of its biggest stars are definitely getting the opportunity to cash in.

This morning's Wall Street Journal details how News Corp.'s (NYSE:NWS) movie studio is working with YouTube celebrity Fred to promote next month's City of Ember film.

With more than 505,000 subscribers, Fred is YouTube's third most popular personality based on channel subscriptions. The brainchild of ninth-grader Lucas Cruikshank, his homemade videos star himself as Fred, a supposedly 6-year-old kid with a rocky home life and a sped-up audio track. There is nothing lavish about the videos, but some of his top entries have received as many as 9 million views.

That kind of traffic is a marketer's dream, so City of Ember producer Walden Media reached out to Cruikshank for a little product placement in future Fred video clip installments. Terms aren't being disclosed, but it's safe to say that Cruikshank will be making far more than the country's typical 15-year-old on the deal.

This isn't the first time that Hollywood has tapped hot YouTube properties. News Corp.'s Fox also teamed up with Lonelygirl15 to promote Jumper earlier this year. Knowing that the film wasn't going to have the built-in buzz of superhero blockbusters like Marvel's (NYSE:MVL) Iron Man and Time Warner's (NYSE:TWX) The Dark Knight, it makes perfect sense for smaller projects to go for the viral video score.

Lonelygirl15's popularity hasn't kept up with some of YouTube's fastest rising stars, but the online series did manage to usher in the product placement era by snagging mainstream advertisers like Hershey's (NYSE:HSY) Icebreakers and Johnson & Johnson's (NYSE:JNJ) Neutrogena last year.   

The allure for brand advertisers is obvious, since they receive a ton of exposure without having to shell out major bucks for Hollywood celebrities. As long as the product placement isn't overly forced, it will probably be even more effective than costly, conventional marketing campaigns.

The bigger question is why Google isn't taking advantage of the cottage industry building around its video-sharing site. Isn't it just a matter of time before YouTube goes Hollywood, with the site itself brokering deals on behalf of its most popular personalities? It did something similar with Coca-Cola (NYSE:KO) two years ago, but now advertisers are cutting deals directly with its most popular personalities. YouTube is leaving money on the table if it doesn't take a more active stance, helping YouTubers cut better deals in exchange for a piece of the action.

Taxing the cottages in the cottage industry? It's a start.

Here are some other sticky diversions: