For now, I've removed my Facebook shop from my page on Facebook. It would give incorrect errors for several products over some time.
So, at least currently, I'm only running the website here. I do have both a Zazzle and a Cafepress store, but I don't update them that often. If I can offer the products here, I don't put those designs on products in those places.
There may have been some overlap with some products, but as a general rule, that's how it's done.
This is the place to go for new designs, new artwork, info on works in progress etc.
Just my 2cp.
PS. For the non gamers out there, 2 cp = 2 copper pieces.