PicPlum charges $7/month for 15 4x6" photos (that's 46c per photo).
PePhoto or PhotoCheap charge 6c per photo, which makes PicPlum 7.7 times more expensive.
Seriously, what kind of idiots are willing to pay that much?
Would not invest a dime into this.
The same sort of "idiots" who pay for Guiness instead of Colt 45. Market uptake comes exclusively from perceived value. Penny pinching only matters insofar as it affects perceived value.