Why do people "pack" their cigarettes?

it compresses the tobacco making the cigarette burn better and longer. It also improves the taste IMHO.

Less air between the strands of tobacco makes the cigarettes last longer. Oxygen accelerates the burning. Kinda like blowing on a campfire to to get it going, but a little different.

I also just found it part of the ritual, like tea service. My ritual also included using a nifty little cigarette case, retamping the cigarette on the case before lighting, lighting with a match that was not removed from the book, but rather, using only one hand, tucked under and around so the head was on the striking patch, then struck using only that hand. It really wasn’t part of “trying to be cool,” it was just part of an almost unconscious pattern and habit.

If keeps the wolverines away.

Also, it reduces the chances that the “cherry” will fall off when you ash the cigarette which makes one curse and have to bum another light from the creepy guy outside of the bar.