[I work at Docracy] We check once a day. We've seen some strange stuff going on with "Last updated:" though. For example, if you check out the history of Skype's ToS, they changed it in mid-January, but with a last-updated date of "February 2013"! Then, just a couple of days ago, they reverted it. Here's the first change: http://www.docracy.com/doc/diff?revisedId=0xgv5wfb72v&or..., then they changed it back: http://www.docracy.com/doc/diff?revisedId=0jxg6uxmx4d&or...