Cloud Costs
I'm often asked why we use our own hardware/locations around the globe rather than AWS and other public clouds.
People just don't understand the bandwidth costs involved - Google's $0.12/GB is a bit higher than AWS (depending where in the world you're shifting bits from), but is much, much, much higher than the $0.001/GB we pay in some locations (let alone the locations where we've got free connectivity).
Given we're a bit-shifter at heart, that difference adds up quickly and it's a cost that would have to be passed onto customers (at which point, how do you compete with those cloud provider's own offerings on price?)
It's a particularly nasty cost too because it's unpredictable and driven by the behaviour of others. If you have 100 EC2 instances you know the compute costs, but your bandwidth costs are going to depend on user behaviour. Got hit by a whack of junk traffic? That's still GB's out.
You get similar with backing up to S3/Glacier. It's good you've got a backup, and definitely better than no backup, but the cost of pulling that backup down to restore it might be considerable (depending on size)
Public cloud, obviously, has it's place - there are workloads that it's well suited for, and businesses who's needs are a good fit, but it's very, very far from a panacea