If retail of the future is going to involve a lot more print on demand services, from where are the first 3D printing shops going to arise? Will they be additions to the old photo and camera shops, as a new print kiosk beside the photo printing booths? Will internet cafes install 3D printers for one-off object downloads beside their paper printers? Will they be vending machines standing alone? Will they be in their own service department at big department stores? Perhaps they'll be an important part of novelty shops, who can then print as many weird mugs or toy figurines as they require that day. Maybe they'll find their first niche at the local hardware store, where you can go and get that specific piece you need, the same way you can get a paint colour made to order. Or maybe they will just appear as their own standalone shop, much like current clothing personalisation shops.
Mokalus of Borg
PS - I saw Coca Cola booths at Chermside shopping centre where you could have your name printed on a can.
PPS - But that counts more as experimental marketing.