Is it permissible to give a percentage of the profits to a person who brought a client or a company to be dealt with?

There is no objection to giving someone who brings customers a fixed fee for each customer, as this falls under permissible brokerage (simsarah). However, making his fee a percentage of the profit is not permissible according to the majority of jurists. The Hanbalis and those who agreed with them permitted it, and this is the preferred view among many scholars.