[anonzzzies]

I agree with this if you are talking fb/google scale; you will very likely not even get close to that, ever. But millions of users, depending on how it hits the servers over time, is really not very much. I run a site with well over 1m active users, but it runs on $50/mo worth of VPSs with an LB and devving for it doesn't take a millisecond longer than for a non scaling version.