It would be a wonderful idea, and I think they'll eventually get there. What would be even better: having rarities out there. That way they can sell without going through the costly risky process of packaging them into CD, advertising them, etc.
As an "oldie" of 39, I'd rather have a physical CD release, thank you very much.
As for the cost of 99p a single - I can buy an average CD for £9 with contains at least 11 tracks, if not more.
Go work your sums out!
@brianswig
you know sometimes people dont always want the full album if there is songs on there that they dont particularly enjoy and having the choice of a song might be better for them
perhaps!