Just get a cheap VPS. If you were hosting an application the size of twitter, you wouldn't be asking on HN for advice :-) Seriously, as your application grows,

Just get a cheap VPS. If you were hosting an application the size of twitter, you wouldn't be asking on HN for advice :-) Seriously, as your application grows, you'll improve your infrastructure. Nothing kills a project as easily as building an infrastructure for millions, for an app with only a few users.