Artflakes is a Berlin-based company that hosts artwork on their site, selling it as canvas prints, art prints, digital prints, gallery prints, posters, and greeting cards. Artists can follow each other, post comments on work, and "like" work. Basically, it offers the same products and functionality as Society6 except Society6 is based in the United States (California, I think). Society6 sponsors collaborations with select artists which can turn into printed pieces and/or art shows -- I think that's the only place they differ!
I signed up with both because while each can ship internationally, it's faster and cheaper for customers to order products that don't need to be shipped by air or sea.
I've been with Artflakes for a year, about as long as I've been with Society6. I have yet to sell anything with them, but because they don't charge any fees (besides their cut of whatever you sell) and because they are in the European market, I'm definitely sticking with them for now!
Oh, and also -- Artflakes is another site that is respectful of the copyright of the artists they host. I can't find that stated on their website at the moment (it's gotta be on there somewhere!) but I emailed one of the founders and asked, and they make no claims of ownership of the work that is posted. I think if you are interested in joining the site they will email the terms of agreement and such.
Hope this was helpful!