What's that song?

We were cozily ensconced on the couch watching Austin City Linits (Jason Mraz/Fountains of Wayne from last week - great show) and it occured to me: hey! why is payola illegal but all the drug reps can hand out endless swag to get docs to prescribe and that's totally okay? Legally, I mean. I have serious ethical issues with it though I will freely admit I also have a lot of said swag so I'm probably a hypcrite. I heart my Zoloft mug! Just don't put it in the microwave.

Husband specualted it's because the airwaves belong to the government and you need a license to use them, but stations sell acess to them all the time: advertising. Drug dispensing requires a license as well, so shouldn't the dispensing of toys, trips, magnets, pens, whatever, be as illegal as the A&R rep trick of sending a left shoe to a DJ, promising the right one upon completion of X rotaions of Y song?

Seems to me it oughta be. Or else they should both be legal. Or maybe I'm missing the point entirely. Quite likely, actually.

Does anyone out there know the technical details on the whys and wherefores on this?