Quoted: Mosso scales automatically and additional capacity kicks in as you need it. There's no hardware to buy and you only pay for what you use.

Quoted: EC2 lets you host your web site on Amazon.com’s servers. The service makes it look like your application is running on your own cluster of dedicated physical servers, when in fact these servers are being simulated using CPU virtualization technology.

You just upload a hard disk image to Amazon, and then you can add and remove virtual servers running that disk image as you need them to meet the demands your site’s traffic. And best of all, they cost a lot less to run than real, physical servers!

Quoted: Reliable, affordable web hosting service. Grid-hosting.