Music distributors arent able to deliver the same album to the same store, this has always been exactly the same in the CD era.

We will never prevent you from doing anything you want with your music.

For YOUR sake, though, please note: If you sign two digital distribution deals with two companies that will both be sending the same album to iTunes™, Rhapsody, etc – this will hurt you, because the retailer will usually remove the album completely until you decide which distributor has the exclusive right to be selling that album through them.