WTF... Network hashrate 3.28 GH/s, i found only two pools, one with around 5.45 MH/s the second with around 2.25 MH/s... someone is solo mining really hard or there is other bigger pools?
It's a mix of a few big solo miners and some private pools. I still solo mine at home on 5 machines, for example - I get a block every other day or so. You don't have to be huge to solo BBR still.
Not sure if it's still happening, but for a while, some of the big EC2 miners would run their own pool inside EC2 to keep the bandwidth charges down and latency low.
If you've got more than about 1-2MH/s, I'd solo, but that's just me.