mhansen - 8:18 pm on Jul 8, 2011 (gmt 0)
I revisit and optimize my busiest pages every month. Sometimes, spending more time on an existing page, than I do on new content.
I keep a log of the exact changes I make each month, to see which worked, and which didn't. (Every page and/or change also has a goal, ie: click, subscribe, buy, etc)