ecrater is great! I am pretty much exclusively selling on there because it is free and it works better for what I sell. I just opened my store last week so I haven't had any sales.
I have been very active on the message boards and have found that success varies. I see reports of no sales to sales of $1000's a month.
You really have to work at promoting your site. The posters on the forums are awesome and there is a ton of resources to help you with marketing.
My store is www.outfitkit.com