The problem with that is that most of those hosts also have some odd, not always up front limits and worst case completely shut down the site with a "Bandwidth Exceeded" message until next month. You don't need dedicated hardware for a start up game, a VPS is a good mid way point with more control than a shared AMP server but less cost than a dedicated. In the other thread about shoehorning HTTP into a role it wasn't designed for I posted a link to a VPS company who's minimum plan was $4USD a month (albeit the stats are kind of piddly for a medium traffic server like matchmaking, the next one up's only $7). Usually by the time you've outgrown the stats for it you're making enough to upgrade to a more permanent solution, if not at very least the next tier plan.

I do not have any bandwidth limits or memory limits so for me it is a easy choice even though I admit an VPS or dedicated server would be nice.