FYI I know Yahoo photos used Target, Sams Club uses themselves, one of them uses Walgreens, etc.
Buying the photo printer and then buying the paper and keeping it restocked isn't cost effective. A 4x6 cost like $.17. Heck my 20x30 hanging behind me right now was only $19, and you can't print that on a consumer printer.
Worth noting, out of 8000 pics with my DSLR and 10,000 on my FZ5, I have ordered >300 in hard copy.