I was just checking them out, and it almost appears that you don't have to keyword or categorize images until after they are reviewed.  Am I right about that?

Has anyone checked them out? 

Nevermind - I just figured out how long they've been around

I dont know how it performs but you can see lots of snapshots there and look at their forums last post: oct. 2007.
Also look at the sales of their top contributors:
Y.arcurs 179 dws

riffmax.... there are plenty of threads on usps going back years......   they have a history around here... 

check out their stats...   largest folio vs sales     you should quickly see for yourself if  it is worth it.  btw,  I was with usps for over a year, emphasis on was. 

I'd forgotten all about this site - it was down for ages and I thought it had folded. I just checked the site and found I have a balance of $80 I have only uploaded 650 images out of 8000 on the site so pleasantly surprised. Don't think I will bother uploading the rest but this is a nice bonus. Pays for my gas this week!