Great! I love this show so much. I used to watch it as a little girl (no, I was not brainwashed into thinking I needed a tiny waist), and I liked it then, but now, as a teenager, the show seems even more amazing.
The humour is witty, the characters are great, and the episodes are overall refreshing, not to mention some great one-liners ("What are you shopping for, Kenny-Boy? A personality?").
The only thing I would say is that it's not really appropriate for too-young children. I'd say it's 10+. The show is a parody of Barbie, poking fun at the world they live in, it's a comedy with no real conflict, and while it's apparent to a kid over 10, it would be more subtle to a younger child. There is a lot of stuff about dating, and a few jokes that a child wouldn't really understand (not inappropriate).