MySpace Music hopes the release of Eminem’s newest album will help prove the promotional value of the site to record labels.

The music service, which bowed in September, has launched its biggest promotional push around a single artist with a campaign that covers multiple platforms, including the Web, TV and events.

Effort began Friday, when MySpace Music preemed Eminem’s “Relapse,” streaming the album for free before its release Tuesday.

On Sunday, an animated Eminem made a guest appearance during interstitials that aired during Fox’s “Family Guy.” Aim was to send viewers back to MySpace to listen to the album and find out how to get free tickets to a concert Eminem will perform in Detroit on Tuesday.

Two songs from the MySpace-sponsored show will air on ABC’s “Jimmy Kimmel Live” on Friday, May 22, one during the show and the other during the credits. Entire concert will stream on MySpace Music days after the appearance on Kimmel’s chatfest.

“For us it was a great way to show different synergies” between various News Corp.-owned properties, said Courtney Holt, prexy of MySpace Music. “We love the idea of online and offline working together. It shows the power of the medium.”

“Family Guy” was chosen because the toon is one of the most popular shows on MySpace. Its on-air audience also fits well with Eminem’s target demo.

“Sunday night is such a great demo for Eminem fans,” Holt said. “It’s one of the largest and powerful aggregate of male youth that are watching TV.”

MySpace Music has also launched major efforts around Guns N’ Roses, Beyonce and U2 and plans another considerable push for Green Day. The cross-platform effort for Eminem signals the kind of promos MySpace will launch in the future, efforts that will eventually incorporate mobile and other methods.

That’s good news for record labels looking to raise awareness for their acts, especially their album launches.

“This will set the tone of where we’re going with this business in the future,” Holt said.