I know it's not exactly in vogue these days to tout the merits of bare hardware, but.. after all the VPS hubbub over the last couple of years, the best progression for your website still seems to be:<p>1. No traction? Just put it anywhere, 'cause frankly, it doesn't matter. Cheapest reputable VPS possible. Let's say, Linode.<p>2. Scaling out, high concurrency and rapid growth? DEDICATED hardware from a QUALITY service provider--use rackspace, softlayer et al. Have them rack the servers for you and you'll still get ~3 hour turnarounds on new server orders. That's <i>plenty</i> fast for most kinds of growth. No inventory to deal with, and with deployment automation you're really not doing much "sysadmin-y" work or requiring full timers that know what Cisco switch to buy.<p>3. Technology megacorp, top-100 site? Staff up on hardcore net admin and sysadmin types, colocate first, and eventually, take control of/design the entire datacenter.<p>I simply don't understand why so many of these high-traffic services continue to rely on VPSes for phase 2 instead of managed or unmanaged dedicated hosting. The price/concurrent user is competitive or cheaper for bare metal. Most critically, it's insanely hard to predictably scale out database systems with high write loads when you have unpredictable virtualized (or even networked) I/O performance on your nodes.