As an unbiased outsider (don't lie my moderator powers fool you), I can say that the Unity licensing restriction are silly and stupid.
ArenMook has earlier stated that he has no interest in hard-lining the licensing restrictions imposed by the asset store. In my opinion the draconian licensing scares off more people than it ensures will pay for it.
In short, it's on a "don't be a dick about it" license - 1 license for 1 company. Don't distribute it to friends or other companies, but within your own company is fair enough; I mean, how would anyone check up on that anyway? Since it's "raw" code, it has to be in the project for anyone to be able to work on it, so everyone would have it whether they "use it" or not.
I do commend you for reading the licensing though, you could quickly end up in a bad situation...
http://www.youtube.com/watch?v=FZ23kosLFec
