I just got day 2 and 3 today and i got day one yesterday. my best guess is that the lights on the envelope are what we should be paying attention to. and yes i know im just repeating what everyone else has already talked about.
also if you look on the back of each envelope it tells you when and from where each shipped, so the envelopes from brockton are different than the ones from sylmar. mostly i think because the ones from CA were done digitally.
it is the epidemy of an addicting casual game. its simple and you do it on your phone/ipad for a few mins at a time. you save up money to buy tools that make it so you can do the work easier. i like it as much as i have liked any casual phone game.