Even when my last DD was involved in scouting-12yrs ago maybe- the trend was moving toward "booth sales"
for many of the reasons others have mentioned. Safety, time etc. The troop really gets very little of the money. I think it was 35-45 cents/box when my girls were involved. the rest went to the GS council. At least around here the money earned went to the troop as a whole, not into an account for the individual girl to use for camp, etc.
Thats was one reason i liked the Boy scouts way better. Anything my DS sold, the money went into an account in his name to pay for camp, high adventure etc. We rarely had to pay fo him to do anything, it all came out of his account and he did alot!