Gizmodo pulled together a great synopsis of a learned and high-fibre article from the Columbia Law School’s Science and Technology Law Review. It deals with the difference between buying and licensing and what that means to consumers of dowloadable e-books.
First Sale
Some users have argued that these license restrictions violate the “first sale” doctrine. Under the Copyright Act, the first sale doctrine allows the owner of a particular copy of a work to sell, lease or rent that copy to anyone they want at any price they choose. These rights only apply, however, to the particular copy that was purchased; any unauthorized reproduction or copying of that work constitutes copyright infringement. For instance, you can’t give away photocopies of Harry Potter and the Deathly Hallows, but you can auction your paperback on eBay when you’re finished with it.
When it comes to digital works, however, two complications arise: first, consumers might only hold a license to the content, rather than all of the rights that come from a sale; second, without a traditional physical container for each purchased work, consumers may not practically be able to sell their “particular copy” at all.