Amazon Web Services
Amazon Cloud Servers
With AWS you can requisition compute power, storage, and other services–gaining access to a suite of elastic IT infrastructure services as your business demands them.
Social websites and large scale websites
This kind of scalable servers are the best for social websites and large scale websites. When you start your website with millions of page views, building on a large dedicated server costs very high, though, building on a small server first and moving to a large server later is quite risky and very difficult sometimes.
In such a situation, scalable web server like Amazon Web Services is very useful. Start with small size servers, then you can upgrade seamlessly to high-performance servers as it requires.