Um.... are datacenters free now? Did i mis-hear the fact that they've spent several hundred million on building them (and as with any datacenter, most of the kit inside will need to be replaced after 5 years or so), never mind bandwidth provisioning, ac costs, etc.
Having built a couple of small enterprise datacenters myself, I can assure you there are very real costs involved.
I haven't checked out skydive, but google's offerings are all ad based. Dropbox is commercial for anything more than a token amount of space.
I'd rather have zero ads and pay for space as i need it personally.
There is no free lunch kiddos. You pay for ALL cloud services in one way or another. If you don't pay money, your identity and attention is the payment.