1. I really like that you can start using it without registering. I assume that the assigned name is usable beyond "now?"
2. Signup is easy and low-stress (no "how am I obligating myself" qualms).
3. Bug: before I signed up, I clicked one of the suggested wants, and I typed in a want. Then I registered. But in my registered persona, only the typed-in want was on my wish list, the clicked-on want had disappeared. Probably an edge case.
4. It looks like you make your money when buyers click on your Amazon affiliate links for the wanted objects. I wonder if you might make a little more money if you also put an explicit Amazon affiliates box/widget on the side, with a list of related objects?