This is really nice! I didn't mention in the post, but my family friends originally switched from a Secret Santa for the kids in the group to White Elephant, because as people got older it became much harder to buy them things they like.
I think your approach might also help people learn what they like themselves - within my family, the answer to "What do you want for your birthday?" is almost always, "I don't know." Will suggest it!
I keep a wishlist of things I want, and I share that with the family. My wife gets a different wishlist, for the more expensive things.
This year, I put a lot of much more varied stuff on both wishlists that I plan on buying for myself, even if I don't get them as Christmas or birthday gifts. IMO, I should have been doing that all along.
My wishlist is on Amazon, but you could keep one anywhere that you like.
I think your approach might also help people learn what they like themselves - within my family, the answer to "What do you want for your birthday?" is almost always, "I don't know." Will suggest it!