It depends what you need in your datacenters! If you just want servers, and don't care about doing something like anycast, you can find a bunch of local dedicated server providers in a bunch of cities and go to town. But you can't get them all from one provider, really, not with any kind of reasonable budget.
You _could_ buy colo from a place like Equinix in a bunch of cities, and then either use their transit or buy from other transit providers.
But also, unmetered bandwidth isn't a very sustainable service, so I'm curious what you're after? You're usually either going to have to pay for usage, or pay large monthly fixed prices to get reasonable transit connections in each datacenter.
In our case, we're constrained by Anycast. To expand past the 17 usual cities you end up needing to do your own network engineering which we'd rather not do yet.
