I tried exactly the same approach (based on the Lean Startup blog) but I got burned: Google Adwords banned me for life. Seriously! I tried to create another (unrelated) campaign and created a new user for that, and they still blocked me (I guess they are able to track my name through my credit card).

Anyhow, to this date I don't know why (they never explained, and they were quite rude and abrupt on the email). I believe it was because they found out that I didn't actually have a real product. I analyzed the access logs and I believe they actually verify the sites by hand before approving the ad.

In summary, be careful when you use Adwords without a real product.