I sell on Etsy. I have had things listed for several months, and just this weekend made my first sale.
Most of what I have been trying to sell is jewelry that I make (ironically it was a Christmas ornament that actually sold).
I am not sure if things are the same across all categories or if this is more true for jewelry, but it takes some effort to be noticed and get sales. You need to post on their forums and list things alot to keep on the first few pages of stuff. It is more work then I want to do most of the time, I am not really committed to selling things and making money.
I really like that Etsy can give you lots of exposure, and "accidents" do happen. meaning someone could buy the first thing you list, it puts you out their and that is fun. I also like that it is fairly risk free, the 30 cents for the listing fee is worth the chance for a while. I also like that it allows me to tell people that I am online, and I don't have to figure out how to make my own website.
Personally the best thing I got from Etsy is a Hegner scroll saw. I was on Etsy for about a week and I got an email from a local paper asking if I would be interested in being a featured artist. It turns out the editor searches Etsy for new people in the area if she is out of ideas. After the article was in the paper I got another email from a lady who had read the article, her husband had been a woodworker and left behind a library full of woodworking books, a garage full of cedar and a Hegner scroll saw. We met and have become friends and I got the saw.