The phrase "to pay a commission" means that you have to give a percentage of money to someone in exchange for a service they provided or a product they helped sell. Full definition
Woman's day participates in various affiliate marketing programs, which means woman's day gets paid commissions on purchases made through our links to retailer sites. (fsat.ru)
Car dealers often get paid a commission of between 20 - 70 % for selling you add - on insurance policies. (moneysmart.gov.au)
In addition, I believe some management companies get paid commission by contractors. (money.stackexchange.com)