I don't fully understand why companies use AWS. Is it a management driven or engineering driven decision? I assume management - in big companies some exec from Amazon comes to play golf, and in small companies the managers copy what the big companies are doing?
We're small (It's been ... messy. I'm not certain we'll stay. It's easier in the sense that we can bring up arbitrarily many new machines without needing to call Dell when a host gets full, but it's definitely not cheaper. And weirdball AWS-only things get in the way. Oh, and literally nothing is simple or easy in administration or setup.
If I had it to do over again, I think I'd have bitten the bullet and leased more boxes instead.