I will tell you this, my nephew, who is now an officer in the US Army, absolutely loved Minimates. That's all he wanted to talk about with me. When visiting him, we would go out and check local comic shops and TRUs, just to see what we could find.
Also, at one time we had a very active member named BatmitesMom. Her son loved Minimates and she came to the Multiverse to find out as much information about them as she could, because she had a hard time finding them "in the wild". Many members, including myself, sent care packages to that lucky kid.
Interest was there and I really think the medium helped because it was easy to swap parts for imaginative play and simple customization.