I can't speak statistically, but the one I work for now does and the one I'm about to start will too (but in the latter case I'm writing a DBMS, so that's kind

I can't speak statistically, but the one I work for now does and the one I'm about to start will too (but in the latter case I'm writing a DBMS, so that's kind of a pathological example). If all your content is human-generated and O(n) in size, then 10^7 is a lot. The big numbers come when your data is produced by a simulation, or when you're doing OLAPey things with O(n^2)-sized intermediate results. Real-life example: keeping a log of all users, the IPs they've logged in from, and when, and looking for evidence of sockpuppet accounts.