Why not host in house? If you have an application with stable resource needs, it can often be the cheaper and more stable option. At a certain scale, you can buy the servers, hire a sysadmin, and still spend less money than relying on AWS.
If you have an app that experiences 1000x demand spikes at unpredictable times then sure, go with the cloud. But there are a lot of companies that would be better off if they seriously considered their options before choosing the cloud for everything.
If you have an app that experiences 1000x demand spikes at unpredictable times then sure, go with the cloud. But there are a lot of companies that would be better off if they seriously considered their options before choosing the cloud for everything.