Love the idea. I hope it sticks.

I think you should add a statement addressing the privacy issue. Will you or won't you sell data? Is the data encrypted? Will the vendor not sell the data?

I can see this product being a lot of fun. But not at the expense of loss of privacy.

There is a privacy statement on the bottom of the page that covers this. Let me know if you feel this is not thorough enough or not prominent enough.