The Count.It Premium plans allow groups to pay only for what they use, i.e. a per user fee based on participants in active challenges. Groups pay at the end of each monthly billing cycle for activity in the prior month. By default, there is no limit on the number of challenge participants.
However, Admins who want to control their budget can place a cap on active challengers. Once a challenge hits the Active Challenger Cap, it's "sold out," and no other group members can join unless the admin increases the cap.
In this way, admins can manage their budget, and don't end up with "open ended" expenses. Setting the cap is easy:
On the web, log in to Count.It, and tap the settings icon ("gear") at the top right of your group's home screen.
On your Group Settings screen, tap on the Plan option:
On the Plans screen, tap on the Active Challenger Cap option.
On the next screen, you can select the "Limit to" option, and enter the maximum number of challenge participants you want to allow. Once this cap is hit, no additional people will be allowed to join your challenge.