I have a lot of group bookings, they bring huge sums of many in my account.
This month I had 3 group bookings of 12-17 people, and for next month I have 5 of them back to back.
It all depends on the group. The best group was a bunch of students, they went out at 9:00 to ski and came back at 17:00, went out to eat again, came back and went to sleep.
The worst one was a group with lots of small children and infants, they stayed in bed until 10:00, went out at 12:00 came back at 15:00, and stayed up until 02:00 in the morning. And there was always someone staying at home.
Most important is to find out why the group is here and what their plans are. Yes, there are always some small parties, but that is part of the business, you cannot expect these group to not have any fun.