Have you used BOOK2LOOK

[Tonyonline]

I buy my ISBN numbers from Nielsen and receive the odd email from them. Today I received an email for BOOK2LOOK. From the brief look I've had it looks interesting but also, like something I'm going to have to put some work into. Plus, I'm not sure it's even something I could make use of at the moment.
I thought I'd ask if any of you have used it and what you thought of it.