Great idea for impulse buys, no idea how this will work for bands with limited budget. Is this going to be same idea as facebook advertising? Click farms? etc.etc. Pay a set amount so maybe, POSSIBLY more than 1-2% of your followers can see it? (see article: http://musformation.com/why-you-shou...e-on-facebook/
Would be sweet to have some sort of twitter app so hashtagging the band name with "freesong" or something beside it would automatically lead to your e-mail address going to the bands database, and you having a free downloadable song when you got home from the show/dance hall/bowling alley....whatever. I wish Bandcamp had the resources that amazon and Itunes do. Fairer pay out to groups, no mega-monopolizing corporate ladder to attempt to climb. Maybe it's not as innocent as I want to believe (no idea really...) but one can dream.
Smart computer people....make this app!! (please...?)