I feel like there's a middle step missing from this article (or I just missed it reading quickly) - did they build their own data center? Where are these new non-AWS servers physically located?
Renting a dedicated server is very similar to renting a VM. It has a much higher provisioning time, usually hours to 1-2 days. And it takes some upfront cost or a time commitment. But it also has a lot more raw power. So if you don't require the flexibility VMs and the cloud provide they can be a very effective alternative.
They have a US DC now. Though it only gives cloud servers. However even those are still way cheaper than any alternative.
They run datacenters for other datacenter companies. Most people have never heard of them because they're a $6B/year revenue beast that runs behind the scenes; but they also offer direct metal servers.
The article spends a lot of time talking about how much lower their monthly bill is, but it says nothing about how much they spent to buy those 300 servers in the first place.
They lease you the equipment. Yay.
The monthly opex to house and power and cool those servers isn't _negligible_, but if you're doing back of napkin math comparing MRCs to Cloud you can just deduct the costs from their bandwidth charges that have been marked up 10,000%
I put a box of mine in a local datacenter, to their... endless confusion (not only do they not deal with random individuals that often, I actually read contracts so asked questions about why I had to prove my worker's comp payments and some other weird stuff that they removed). Monthly rental payments are about what I was paying in a range of cloud spend, but the system is far more capable, and I can do a lot more on it.