Many programs have a monthly minimum in place. This is initially set up within the program’s contract and discussed when launching the program. The monthly minimum is based on the program’s site commission per month. Your program has a site commission rate which may be based on a percentage of the publisher commissions or sale amount.
For example you may have a $250 monthly minimum for the program. This means that the site commissions for a particular month need to add up to $250, otherwise the difference is owed. If you had $150 in site commission this month you would see a $100 monthly minimum charge on the next invoice. If you are unsure of your program’s monthly minimum or if you have any questions, reach out to your account manager.