AWS or dedicated server?
lsc: I would say "do both"  -  aws is awesome if your site is running slow 'cause you are out of capacity, or you otherwise need a box 'right now' or for only a short period of time.  spin up another instance and be done with it.  But for the boxes you leave on all the time, you are probably better off buying and co-locating your own server.  Usually the capital cost difference is made up in only a few months.The times when a Xen host makes long-term sense are when you want a box that is smaller than optimal.    Right now, I buy dual quad-core opterons w/ 32G ram and 2x1TB disk... assuming I am ok with moderate-speed low-power opterons, it costs about $3K up front.  Hosting, say, another $150/month.  That's a whole lot of ec2 instances.  At those prices, well, AWS is pretty expensive over the long term.But yeah.   AWS is awesome for the servers you don't need on all the time, or servers you don't have time to setup (or your whole ball of wax if your margins are such that paying more for computers won't break your business model.)