Member Rara Avis
Yes, it's been discussed before. A few times. Surprisingly, a lot of people didn't like the idea for their own personal reasons (they didn't want to know someone read but didn't comment).
But the reason it's never been implimented, and probably won't be, is the amount of resources it would consume. A counter works by having the computer maintain a small text file on disk and, every time a page is asked for, increment the number in the file and then serve the page. That's, uh, about 45,000 more files for our web server to track, each consuming disk space and each requiring CPU cycles to manage. Our poor little Ceres already does so much!