Re:All my commercial software is licensed (Score 3, Informative)

It's not the lack of a "First Sale" doctrine in software that makes it licenseable. It's the fact that the courts ruled that making a temporary copy of the software in RAM (i.e. using it) was an infringement of the author's copyright. This brain dead interpretation was made in MAI Systems Corp. v. Peak Computer, Inc., 991 F.2d 511 (9th Cir. 1993) among others.

This allows software publisher to force users to agree to EULA's, because otherwise you can't legally use the product. As far as I know, if you don't use the software or agree to the license, you can still exercise your First Sale rights and resell the application, just like a book.