I've never sold anything there, but I go often to look for things like Duplo's, wooden toys, and used books. Sometimes you can score something great.
Today, they had a Halloween Costume sell, i'd been waiting weeks for this sale. I showed up early, and was able to score a $49 Pottery Barn Kids costume for only $6.99! I never want to pay full price for costumes again.
I don't buy clothes for my daughter there, because we like to buy things such as Tea Collection, Janie and Jack, Hanna Andersson and it's rare that I stumble upon that there. But they are great for picking up pj's at a reasonable price and again, wooden toys.
I have and will continue to recommend them to my friends!