At work, we use a dedicated server provider, so we're; when we identify faulty hardware, we file a ticket, and they swap it out. We still need to have enough bare metal machines allocated so we can turn one off while they fix it, etc; but we don't worry about staffing or supplying the datacenter.

I wouldn't want to switch to AWS from this; bare metal plus a good account manager gives us a lot of visibility and reliability; Netflix blogs a lot about the chaos that is AWS, and we save a lot of effort by having machines that for the msot part just work, consistently; instead of having to deal with instances where performance is variable, etc. Running our own datacenter might be nice for some reasons: more control and information about the network, ability to make hardware choices that don't match the providers offerings, etc; but running a datacenter is a big change.