For a major site with any sort of budget, RAM is a secondary concern. For my small, personal sites that have very little traffic I want as little memory usage as possible. Having a DB server, web server, a few websites including some that run outside Apache and are proxied to (e.g. mongrel) I find myself easily hitting the 256-512MB limits of cheap virtual machines. Upgrading to the next highest tier can sometimes mean doubling my monthly bill. I don't even think of running Java servers.

This isn't a major concern, but I wanted to point out that anyone on a budget will want memory usage to at least be reasonable. It impacts our ability to experiment and play if we are bound by memory constraints.