I'd say that if you want to fund a startup with $100,000 you go meet that startup and get to know it very well. Google is relying on somebody else to make that assessment so my guess is that the cost of those services to Google is much lower than those $100,000, maybe much much lower than that. They sure have unused capacity in their server farm, network, storage, etc. I'm not saying that they're doing an advertising stunt for free but $100,000 worth of anything doesn't necessarily means that $100,000 are leaving Google's pockets.