This should just encourage bands (even the big ones) to explore direct-to-fan modes of selling their music. Bandcamp doesn't take as big of a cut as iTunes. Paramore could have put the single up on Bandcamp and linked everyone there - the most interested fans will be the first to listen, and be the first to buy it, and you make a little more money per sale. Then have it available in every other outlet the day after, for the lazier / less interested folks.
Bandcamp report to soundscan?
I'm assuming that's one big reason major bands don't.