First, it gives me information that I probably wouldn't otherwise get. If there's one concept which "works" for me when catching scum that I wish every other Scummer would follow, it's this: Around D3/D4, re-read D1 completely and in great detail. Shea makes a point about being better off with more information, and this could not hold true more than when examining D1 play. Because one thing that I don't think most players fully grasp is that scum give off more about themselves when there is less information to go around. Scum A will treat Scum B diffrently if B has heavy suspicion on D1 than he will if B has heavy suspicion on D5. I don't think it's ever a conscious thing, but it's almost as though scums assume that they won't be caught by interaction with a scumbuddy (whether bus, defense, counterwagon, or whatever), because they assume that the town doesn't have the knowledge to root out these interactions. On D1, that's completely true. But by mid-game or endgame, when you have more information, these interactions become much easier to point out.
I think this is an important point. It is my firm belief that the most difficult part of scumhunting is catching the initial scum, precisely because you have no reliable associative tells to go on. Similarly, it can be very hard to catch a lone scum. Associative tells are often by far the strongest tells; catching x by how he interacts with his scumpartners as opposed to how he reacts to townies is pretty much expected.
As such, day 1 (and to a lesser extent day 2) are the engine room of the town's scumhunting effort. Day 1 is the day when everything kicks off, when the players who are viewed as "scummy" are split off from those viewed as "town", where most players initial reads are determined, focused, etc. Everyone is alive, so everyone has the possibility of interacting with anyone, and who and how they choose to interact with those players is often crucial.
By later days, it's very rare that new information is being produced; most of what is being considered is based on the previous days. So getting day 1 right, avoiding it being a mess of noise and garbage, forcing players to take stances and put down their positions, and making sure it doesn't last so long that rereading it is an unpleasant task is absolutely crucial to the town's scumhunting efforts. How day 1 goes often influences how the rest of the game progresses to an impressive degree; not in necessarily the outcome of the lynch but in the info gathered.
