[auganov]

You have to look at your profit margins and costs to decide what's the right choice. If you have very low margins and hosting constitutes a big chunk of cost it's very reasonable to get your own servers. If that's not the case aim for flexibility and comfort. AWS is very expensive. Many startups simply have high margins and wasting time on optimizing hosting costs makes little sense.

http://www.webhostingtalk.com/ is a nice board about hosting.