Doing stuff like this helps Google perpetuate their reputation as a company that's doing "cool things that matter" despite the fact that, financially, they're just a big internet ads company. By doing these types of things Google has developed has such a good employment brand that they can get as many CMU CS Masters and Harvard MBAs as they want. They don't need 53,000 of the best and brightest people on earth working on AdWords, so letting some of these people loose on other markets kinda makes sense. Better to let them do it under google's umbrella than someone else's. And besides, they might actually succeed!