The other question is, why not moving to the cloud, it's supposed to be much cheaper.
Although I like the cloud for ease of maintenance, the hardware needs for BOINCstats makes the cloud actually very expensive. I've done some calculations at Amazone and Microsoft and the cost per month would more than double.
To reinforce what Willy said, when the issue of moving datacenters arose a few months ago which would have necessitated a colocation fee that PrimeGrid couldn't afford, I did some research into cloud services such as Amazon and Rackspace and other similar companies.
Most of them aren't all that cheap. Cloud servers have lots of flexibility, which is great for a new web enterprise since you can start small (and inexpensive) and rapidly expand if needed. But that flexibility comes at a price. In Amazon's case, it's not just the cost of the servers: they charge you independently for everything, and nickel and dime you to death. Even worse than the cost, it's almost impossible to reliably predict what your costs actually will be.
The second problem is configuration: most cloud providers offer pre-configured servers with specific characteristics. If that doesn't exactly match your needs, you either end up with a server with less of some resource than you really need, or you end up paying for resources you don't need. For example, you may need lots of processing power, but very little ram, but you'll probably end up paying for tons of ram on a big fast server with lots of CPU.
Fortunately for PrimeGrid, Rytis had experience using a cloud hosting company in Lithuania that's much less expensive than a lot of its competitors. Even better, it allows you to configure your servers exactly the way you want, dialing in the number of CPUs, memory, disk, and bandwidth that you need. For PrimeGrid, this worked well as we had fairly old servers, this hosting company is able to fill our needs, and we could actually save money while increasing performance and reliability by making this transition. Compared to moving our old servers to the new datacenter and continuing to share a rack with BOINCstats, we now have much faster servers, redundant servers (in different datacenters so we also have site redundancy), RAID disks to protect against disk failures, and it costs less than sharing the rack would have cost.
But that company is not the proverbial "silver bullet". There's a limit to how large a server you can get, there's limitations on bandwidth, and various other restrictions that go along with not having 100% control over the servers. It's not a good match for everyone or for every application. There's certainly other places that offer far more capacity and features, but they're also several times more expensive. This worked for PrimeGrid -- but it wouldn't necessarily work for other applications, such as BOINCStats.