It's up to the mod. Some prefer to have a clean slate with each day. We've only recently been using public communication only, before our reboot players were allowed to privately communicate however they wished (necessary for the faction games). I took the no edits/no secret comms rules from Shrinemaiden over to Megatokyo to good effect. Previously we had some day phases that spanned only a page or two.
You can see in the most recent game there are a lot of players still struggling with the idea they actually have to cooperate and act rather than passively wait for detective checks.
Most of the games on Megatokyo are some form of role madness, we used to have vanilla games with around 30 players and only five or six power roles, but the moderator would leave clues based on the attacker's name/sig/avatar etc as to who it was. Some of them were brilliant (like hiding a link in the post somewhere that lead to a fake file not found page but if you viewed the source of the page would have a comment saying a single mispelled word, and then you'd trawl through the conversations to see who said that word or possible reasons why it was mispelled argh so hard) and others were not so. Also it was traditional to leave fake clues pointing to me.
