This is a test of commonsense. Complete the next sentence:

How to calculate commission
Determine what your commission is based on.
Typically, commissions are paid based on the purchase price of goods and services that you sold. However, some companies use different commission bases, like the item's net profit or the item's cost to the company.
Ask if there are any products or services excluded from the commission plan. A company may pay you a commission for selling certain products and services but not others.