Slack is for "small" teams. They've got 10,000+ people in a 'group' since this isn't just for engineering staff, but also for drivers, customer support reps, et

Slack is for "small" teams. They've got 10,000+ people in a 'group' since this isn't just for engineering staff, but also for drivers, customer support reps, etc. These guys aren't split into lots of multiple teams under one big company, they're all just one 'team' with people leaving and joining fairly often due to driver turn-over. Slack would cost ~$100,000 a month at those numbers as well (given enterprise level discounts).