What are the pros and cons of using dedicated servers versus Aamzon EC2 for hosting a high traffic website - that has about 2 million visitors and 5 million page views a month. The content is mostly dynamic and served from a database. Does anyone has any experience of the costs and performance for such a setup.
Amazon EC2 is going to be much more cost-effective versus dedicated servers from my experience. Should you experience a sudden rise in the volume of traffic to your site all you need to do is shell out some extra $$ to Amazon and voila your site can handle the traffic (assuming there are no coding bottlenecks). Unless you have a truly massive website (ie: Facebook) the benefits of hosting on Amazon EC2 far outweigh the risks.
One of the only risks that you take with hosting on EC2 was showcased a few months ago when the whole cloud went down, taking Foursquare, Quorra, Reddit, and other multi-million user base sites down along with it.
From a user experience I believe interaction with the cloud hosting provider is pretty much the same as interacting with a dedicated server, so the only real concern to take into account would be cost-effectiveness.