Security

The reason that companies claim to prefer a private cloud solution is security.

Amazon datacenters are far more secure than any private datacenter, due to both strong security policy and anonymous user data. Security is not about exploiting encryption algorithms, like in Hollywood movies, but about social attacks that are far more fragile. Few companies take care of administrative, financial, familial, or personal safety.

Thanks to the combination of VPN, HTTPS, fixed IPs, and firewall filters, you can safely deploy an application on Amazon Cloud as an extension to your own network, to access data from your legacy Oracle or SAP mainframe hosted in your datacenter. As a mobile application demonstrates, your data is already going out from your private network. There's no concrete reason why your backend application can't be hosted outside your walls.