There are various levels of Scalabilty, AWS being one of them in a chain. Hosting > AWS > CDN's like Akamai > building out your data center similar to google.

There are various levels of Scalabilty, AWS being one of them in a chain. Hosting > AWS > CDN's like Akamai > building out your data center similar to google. AWS is a good start, and if you start doing 100's of Gbps of traffic you should probably start looking for other options. As the other HN commenters have mentioned, you have to architect you application with scalability baked in. Some applications aren't good candidates for scalable applications such as many 1-1 live streams.