I do pretty well out of serverthiefbait.com, despite having built it in a weekend and not touched it for 1+ year...
Did you really build all of it in a weekend? And customer support is fully automated?
Yeah - the whole thing is appengine, fitting fully in the free tier, and getting the html template for that home page working on every browser was the hardest bit. There's no login or anything, and the database is just one record per sale. Wallets are all pregenerated. Checking for theft just involves polling a block-explorer API and sending a mail if anything changed.