Maybe it wasn't AMD, but they already had a massive fleet of GPUs. It wasn't running Dremel, either. Or maybe they found a way to do that, too, I don't know, but there are already enough workloads at Google to keep GPUs well fed.

I know from experience that Google is very cheap. You tell Urs you saved a million dollars and he'll ask you why you didn't save two. Or five.

If this takes off, the pricing of the service will pay for the hardware (assuming they did a reasonable job there of baking it in). Even if it doesn't, organic growth from other, much larger Google services can make use of the idle hardware.

For the record, I was involved in a couple of projects that required a lot of new hardware. One of them even ended up saving the company a lot of money in a very lucky, definitely unintended way.