$10 million plus is what Portfolio.com's "back-of-the-napkin" analysis estimates as the licensing potential for Led Zeppelin's "Stairway To Heaven". Thus far, the value of the song's earnings--for public performance royalties and sales alone--is $562 million. Keep in mind, there are multiple albums by the band containing equally incredibly classic and amazing songs, so multiply that by ten or fifteen or fifty or so and you've got a good idea what that might look like. On paper. Or in your bank account.

Much was made when Zeppelin et al agreed to license "Rock and Roll" for the Cadillac commercial campaign; they own their own publishing--a rare, glorious thing for a band of their stature--and have much more control of their work. And indeed, that rare license rankled fans. But why the band could potentially make millions of more dollars but doesn't is neither here nor there. I don't think it's a question of needing more money or having enough--Cadillac commercial aside--it's that they don't need the exposure.

There's a bit of schizophrenia going on in the general public's mind in regard to licensing, particularly for commercials. The selling out debate has its ebbs and flows and lately it's been in ebb mode. But it's always been there--The Who released an album about it, The Sex Pistols openly swindled fans, and Carly Simon finally managed to shock people with a ketchup endorsement.

On the flip side, there's commentary like this, heralding the emergence of TV as the new radio. New artists are simultaneously selling their music along with the product. These commercials are in heavy rotation, artists don't have to "pay" for the exposure (quite the opposite) unlike commercial radio, and the song, in a national commercial campaign, reaches a huge amount of ears.

Basically, TV exposure is for the young. The public accepts that a new band needs the income and the exposure, and also discovers new music this way. But Led Zeppelin is already embedded into their iPod as well as their musical being. It's a badge of taste and distinction. And if ever Feist or Joe Purdy or the next artist with a hit on an iTunes commercial lasts half as long or consistently writes and records music a third as good as Led Zeppelin, then they too eventually will be seen as selling out because by then, they don't need to advertise their wares no matter how much they get paid to do so.