As we all know, nonmembers have a harder life around Jamaa. They can't change clothing colors, they can't buy pets, and they can't buy certain items (and no dens).
But there is a reason for all this. Think of AJ as a business, a store can't go around selling things for free, right? They would go bankrupt! It's the same with Animal Jam, they have to employ people to work on the site, and they have to pay those people.
So what I'm saying is, without memberships, there would be no Jamaa! AJ has reasons for what the don't let nonmems do, it's so they join! In the adult world it's all about profit, that's how the world works.