After searching the web I still can't find the reason to use EC2. What's the point to scale EC2? If you expect a huge burst in traffic, they say.

OK, but what if you already have a couple of sites with good traffic, and for example medium reserved EC2 instance is not enough.

You are paying $36.60(medium reserved for 1year) in EU(Ireland) + traffic + optional expenses for databases and S3 if you use them.

Of course as some point when you are under $56.6-$66.1 you can optimize your hosting costs with Amazon EC2. But when you get at some point if purchase EX4 server from Hetzner, it will surpass your perfomance needs for a long time, before you get a massive traffic. (I am wrong?)

CPU: i7-2600 Quadcore (3.4-3.8 Ghz)

RAM: 16 GB

HDD: 2x3 TB SATA (6 Gbit/s) - I think that disc performance of a dedicated is better then of Amazon EBS

Traffic: 10 TiB in month included. This is what you get from Hetzner for $56(- 19% VAT) or $66 for EU residents.

Please, tell me what's the reason to use Amazon? Which load won't a server from Hetzner take, but Amazon Auto Scaling will?

The maintenance of dedicated vs EC2 is still the same? Or hardware failure at Amazon, won't ruin your EBS storage?

I'm still not at the level when I need expensive hosting, but want to know beforehand, just to be sure if Amazon infrastructure is better then pure performance of Hetzner's hardware.