NEW YORK (AdAge.com) -- Hulu doesn't like to be perceived as competing against TV, but that's what McDonald's has the web video site doing with a new campaign for its line of upscale coffee drinks, McCafe.

The fast-food chain is promoting a commercial-free "prime time" on Hulu tonight, starting at 7 p.m. ET and lasting eight hours until midnight on the West Coast.

During that period, thanks to McDonald's, all shows from all networks will stream without advertising, except for a branded frame advertising the McCafe.

McDonald's bought all the available ad spots across all shows during that time period and is promoting its largesse with a countdown clock on the Hulu home page with "Family Guy" character Meg and "30 Rock's" Alec Baldwin. When users click on the McCafe display ad on Hulu, they are directed to a microsite for the coffee line.

A Hulu spokesperson said the program is a test, and that Hulu has no intention of creating event-programming or driving viewers away from the TV. It's one of several experiments planed for ad-free periods, even days on Hulu.

Danya Proud, a spokeswoman for McDonald's USA, said the campaign isn't about turning viewers away from TV, but about following the consumer "as their interests change and the avenues for how they get information and interact with brands change."

Indeed, Ms. Proud said McDonald's will also be advertising on TV for McCafe in prime time. "If you look at the [media] plan, it really is a nice mix of multimedia; we have aggressive TV commercials, radio, outdoor billboards, some digital executions."

McDonald's wanted to roadblock the site to maximize impact among Hulu's 42 million monthly unique viewers. The buy comes amidst a massive push by McDonald's to steal share for its coffee line from the likes of Dunkin Donuts and Starbucks.

The effect, however, is to give viewers a strong incentive to spend some time with Hulu over the same programming on TV.

Hulu has taken great pains to keep its joint venture partners -- which now includes ABC/Disney -- comfortable that Hulu viewing doesn't detract from TV ratings. At the behest of its network backers, Hulu blocked Boxee, which makes software intended to stream web content on TV screens.

But it's another innovative ad unit that helps Hulu's bottom line. The ad campaign was sold through Hulu, not via one of the network partners, and it includes significant display advertising, which is revenue it does not share with its content partners.

On video ads, Hulu shares the majority of proceeds, usually about 70%, back to the studios.