[puzzle]

I'm an ex employee. There's actually a whole team whose sole job is making sure that all other teams have policies, measurements and alerting for deleting data. They'll chase you if any of the above doesn't hold. It's non-trivial work and slows down your development, if you believe in releasing early and fast. For everybody else, it makes total sense.

I bet it's not free to run, but it's cheaper and easier than elsewhere, because Google's infrastructure is built in-house and mostly integrated. I don't envy other companies that want to do the same.