as someone who shoots for a living i can honestly say that dothpoto's prints are pretty crappy... their machines refuse to recognize embedded icc profiles... this isn't much of a problem for most people, but it is for me since the standard srgb does not offer a wide enough gammut for some photos... even when saving the files with srgb the results were off on color, way off... regular prints come out a bit darker and murkier than needed... the prints that were meant to be darker come out with their highlights blown out... in general it looks like dotphoto runs a very generous auto-levels command on all images before printing... this may work well for some, but it pretty much ruins most of my prints... i ordered though them 3 times, and will never do so again...
walmart has been hit or miss for me... i was dissappointed with online prints, but when shooting a tournament in Pa i needed some quick 4x6's and the local walmart did a fantastic job... the kid behind the counter knew exactly what i was asking him and did a great job... the girl at the local walmart (long island) had no clue and the prints came out terrible...
if you guys are looking for a cheap good printer, the place to try is epixel.com... i've had great results with the place... they use a Fuji Frontier printer with crystal Fuji paper... pretty much the same setup as Walmart and dotphoto, but they seem to know what they're doing... it's $0.25 per 4x6, which is all i print from them... i think they have photo sharing and album services as well, but by the looks of them that's not where they get their business... 8x10's are $3.00 which is more than some other places, but the quality is dead on... i've uploaded tiffs there, both 16 and 8bit and they didn't seem to have a problem... one of my colleagues prints just about everything there, i've seen some of his 30x40's and the print quality is great... the results are consistent from all 3 cameras i use (canon 1d, d60, d30)...