Traffic didn't change much, but user behavior definitely did:
http://minimaxir.com/img/reddit-statistics/all_score_reddit....
http://minimaxir.com/img/reddit-statistics/all_comments_redd...
http://minimaxir.com/img/reddit-statistics/all_score_reddit....
http://minimaxir.com/img/reddit-statistics/all_comments_redd...
In fact, that was a main reason cited be people at the time as to why they liked reddit over other options -- because we didn't artificially inflate page views by forcing reloads.
Jul 2010,"7,275,451","279,891,841"
Jan 2011,"12,284,583","590,531,477"
And then a couple months later we realized we were undercounting and it jumped again. :) Feb 2011,"12,654,137","594,987,855"
Mar 2011,"16,925,815","1,133,827,794"Fortunately you had just turned up a bunch of new servers just days before.
We call that "capacity planning". ;)