How should i advertise?

I'm trying to sell a computer i built but i'm not having much luck. I'm trying craigslist currently and have had no dice there for over two weeks. Here is my ad if you'd like to see cosprings.craigslist.org/sys/310325...
I've also tried facebook and ebay classifieds didnt even upload my ad. i feel like i'm targeting a very low portion of my potential crowd, especially since many people don't even trust craigslist. So how else can i advertise? How can i get many people to see what im offering? I'm out of ideas and am also new to this so i've come to yahoo answers for your support. Thanks!

Nice box.

Your best bet would be to try eBay again. They've got the traffic. Run it as an auction, possibly with a start/reserve of around $550 if you can afford to go that low. People don't have money, so they're searching for bargains.
Good Luck.