I built http://artistsnclients.com - It was an idea I had back in 2011 but couldn't find time to do. Now I built it, but it doesn't seem to be viable. I had a few people test it and the profit is at about $4 right now.
At least I improved my skills a lot thanks to it, especially in regards to financial processing.
There are some real gems here, it's a great concept and I think it's worth putting in the time to make it shine. Maybe hit some people up on other artist sites like deviantart and ask them to submit to beef up the portfolio. I commission art for various occasions and it's also a great gift idea, eg. http://artistsnclients.com/slots/13
At least I improved my skills a lot thanks to it, especially in regards to financial processing.