It all depends on how many servers you have, as well as what sort of databases/database complexity. For a laughably trivial site, a single host could do a lot

It all depends on how many servers you have, as well as what sort of databases/database complexity. For a laughably trivial site, a single host could do a lot of requests per second without too much effort. For a normal Rails app running on a handful of hosts, 100 requests per second is nothing to scoff at, especially if you're on your own.