It can be true that all the big clouds/cdns/websites are in all the big colos and that big tech also has many owned and operated sites elsewhere. As one of the

It can be true that all the big clouds/cdns/websites are in all the big colos and that big tech also has many owned and operated sites elsewhere. As one of these big companies. You've got to be in the big colos because that's where you interconnect and peer. You don't want to have a full datacenter installation at one of these places if you can avoid it, because costs are high; but building your own has a long timetable, so it makes sense to put things into colos from time to time and of course, things get entrenched. I've seen datacenter lists when I worked at Yahoo and Facebook, and it was a mix of small installations at PoPs, larger installations at commercial colo facilities, and owned and operated data centers. Usually new large installations were owned and operated, but it took a long time to move out of commercial colos too. And then there's also whole building leases, from companies that specialize in that. Outside the US, there was more likely hood of being in commercial colo, I think because of logistics, but at large system counts, the dollar efficiency of running it yourself becomes more appealing (assuming land, electricity, and fiber are available)