I have been using the site since it was in beta testing mode, I have made £51.65 commission from the BMX Bikes site in my sig just in the last 12 days from 3 bike sales, I made another sale today, only £0.70 commission for a cheap item that was sold this time, but still, it's another sale and they all add up.
Personally, I think it's a great site to use, I have added other domains to it, got 11 stores on their in total now and will be adding more. If you have a good traffic domain name you will certainly do better than parking.
It's very easy to set a store front up, from adding your domain and pointing your nameservers to myaffsite, I can have a fully functioning site online in about 10 minutes, then just play around with the keywords to draw from the retailer feeds, excellent site, that's my opinion anyway.