I've had several people test the product in these first few weeks, and have gotten some interesting feedback from it.
I've had confirmation that Pin Garden is designed for a niche market (which I knew) and primarily for business use (which I didn't fully realize).
I'll have to evolve the communication a bit based on these considerations.
I was surprised to receive few complaints about the strict limits on the number of spaces.
The last missing piece before expanding the circle of users is the integration of a search engine.