Yeah, thats what my friend tells me as well. He works at Google. Yet I still don't trust it. Any computer system needs programmers, testers, QA folks and production readiness tests. The ad system they are building needs raw data. Unit test data, Assembly test data, System test data...etc. They are all under NDA, I'm sure. But no system would go live without using real data for test purposes. Same with production support.
Its moot anyways though. I get POP3 access to yahoo mail and they give 2GB of space.
Their ad system doesn't really need testing. It is the same ad placement system that their search engine uses and has been using for quite some time now.