It's not requiring a license, it's a distribution agreement.
It looks like they want you to fill out a distribution agreement so they have some idea of what kinds of systems the reader is being deployed to. From what I can see, they want to verify your company email address as well as tell them how many copies you intend to distribute in the next year.
http://www.adobe.com/products/acrobat/distribute.html
and
http://www.adobe.com/products/acrobat/acrrdistribute.html
Neither is requiring payment or licensing. They're just protecting their product from unauthorized distribution of inappropriate versions to systems it won't run on, since they don't have the ability to check the system requirements themselves that these copies would be distributed to.