It's hard not to notice: Indie bands seemingly soundtrack just about every sitcom, film and television commercial today. But why? Influential music supervisor Alexandra Patsavas swears it's not just about cheap labor.

"It's far more of a creative decision than a monetary one," she says. "We're picking out the kind of music that the characters in the show might listen to."

Patsavas worked on the music for The O.C., known for breaking indie bands, as well as Grey's Anatomy, Roswell and The Twilight Saga, the latest of which comes out Nov. 16. Since 1998 she's run her own Pasadena-based music company, Chop Shop Supervision, which became its own record label five years ago.

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It wasn't always this way. In 1984, Miami Vice became the first series to eschew the old-school made-for-television soundtracks in favor of pop music. But in the 20th century, Top 40 hits rarely made it into commercials. Nick Drake's "Pink Moon" was a game changer when used in a Volkswagen ad in 1999, while Moby's licensing of almost every track on his album Play that year may have been the tipping point.

Steve Jobs certainly took notice. Throughout the next decade, iPod media campaigns launched one indie rocker after another to fame: Consider Jet, Feist and Yael Naim, which helped them gain careers and helped Apple stand apart. This trend became a new business model, as advertising -- previously closed to alternative musicians -- became a new conduit to the Billboard Hot 100.

The days when peddling one's music got you labeled a sell-out are long gone. Bruce Springsteen famously declined millions to keep his "Born in the USA" from a Chrysler ad, but Bob Seger took Chevrolet money for "Like a Rock" and Led Zeppelin peddled "Rock and Roll" to Cadillac. Those Victoria's Secret ads, meanwhile, did little to tarnish the Black Keys' credibility.

What kind of money are we talking? Billboard.biz says the payment range for national campaigns can start from four to five figures per track for an unsigned artist to the high six figures and beyond for a name act. In some cases, this type of work has opened doors to recording contracts, so much so that CNNMoney wondered if advertisers had become the new labels. In that case, wouldn't music supervisors be the new A&R staff?

Patsavas doesn't agree entirely. "I think supervisors really have a different goal: to find the very best song that will enhance the story. The job's not necessarily going to go to the best-looking band, or to a musician in a certain age group. Often, when a song hits, it hits because it was tied to a scene that fans liked." She adds that she hears about new music by scanning music blogs, as well as getting some 300 promotional CDs per week. She may be modest about it, but many groups' hopes and dreams undoubtedly live in that pile.

• Music Industry