I have sold much more on Zazzle than Redbubble, but a lot has been the same design. (word of mouth I think)
I make more $$ on Redbubble too, but I think I have sold 2 phone cases.
I just wish Redbubble was a little more customizable, and offered more products.
I tried Society 6, but I had issues with design size. I don't have photoshop, or even any type of good editor on my big PC, so that hindered me.
Liz...your stuff is awesome...I bet it does sell really well.