CBS's Last.fm Offers Free Streaming Music. Yawn.

Last.fm's big announcement? Not so big. CBS has inked deals with the four major music labels to allow Last.fm to offer free on-demand streaming of a large -- but not complete -- catalog of music. That's it.

But CBS made the most of the deal, trotting out CEO Leslie Moonves, digital chief Quincy Smith, much of the CBS Network's sales staff and Last.fm founders at a press event this morning to announce the new deal, which isn't groundbreaking. Napster has had a little-used on-demand streaming service for a couple of years, and imeem now offers a version as well.

It's also a bit limited: Users can only stream a song three times, and the catalog looks like it has some gaps -- we couldn't find full tracks of Led Zeppelin, for instance, and of course Web holdouts like the Beatles are still AWOL. The biggest news, really, is that CBS is throwing its weight behind ad-supported music, which is quickly establishing itself as the music industry's new "this better work" strategy.

CBS has laid low on Last.fm since it was acquired in May for $280 million, but that's about to change. The service is about to get huge promotion an all CBS assets, including radio, TV; it will get a big push on next month's Grammies -- thought the writers strike may sap that show of much of its value.

Update: Quincy says this is, in fact, a bigger deal than we think. Video is part of it; the site has a bunch of them and will get more. "We'll get there, but not now," he says. What's more, Quincy stresses, CBS isnt just pushing ad-supported music, its landed big advertisers like Toyota. Duly noted.