Google owns the stuff you make during 20% time, iirc, so they use it as a feeder for new products.

Allegedly (I can't verify, but can't see why they'd lie) GMail, Google Maps and AdSense were all born out of people's 20% time and Google just swooped in and turned them into full on products.

It might be worth staying #3 in cloud if they could pull off products like that again. I can't help but notice that those products are all old, though.