Lesser known product knowledge

Two of my lesser known what I consider hidden gem "hit" products are the Body Language Generator and the Dream Generator.

These two generators, although not overly popular, have picked up the most buys by people that haven't bought anything else from me.

I'm not sure why they attract, what I consider such an almost cult-like pattern of consumers.

I'd like to build something off of both of those—maybe something based on mixing up both.