The Amazon AWS Premium

Until the early 2010s we ran our own tiny data center (six to eight racks in two separate locations). When we re-evaluated whether to have the racks hosted somewhere else, it worked out way cheaper to run the machines ourselves. But when we included the costs of the sporadic stuff, cloud providers became cheaper.

The sporadic stuff adds up. This is the "other stuff" one needs to do to keep the machines running. It includes the time it took someone to swap a failing drive, or the loss of productivity when the system went down (because of faulty air conditioning maintenance procedure), or the costs of procuring hardware, or dealing with the network provider, and so on. This stuff adds up. We ran a tight ship. Every minute someone spent dealing with the racks of computers was a minute they did not spend creating a product for our customers.

The only thing we had some difficulty with was intermediate reliability storage, at the level of non-raided spinning disks. But that was then, when the offerings where thinner.