> If you don't have the experience in-house, and don't want to manage your own servers, that's 100% legitimate, but don't assume beating Amazon's uptime would be hard.
The relevant questions aren't whether you can beat Amazon's uptime but:
(1) How much is it worth to beat Amazon's uptime by the amount that you're likely to beat it?
(2) Could you produce more value by spending the time/money that it would take you to beat Amazon on something else?
One other point to consider is that while AWS provides nice scaling and availability features, it still has some latency issues to work out. Latency between two EC2 instances will be higher than two systems you are running on the same LAN, so if you need high-throughput/low-latency communication between nodes you should probably also run your own server farm.
The relevant questions aren't whether you can beat Amazon's uptime but:
(1) How much is it worth to beat Amazon's uptime by the amount that you're likely to beat it?
(2) Could you produce more value by spending the time/money that it would take you to beat Amazon on something else?