Conn. Gen. Stat. § 42-145: Contingent consideration void.

The advertisement for sale, lease or rent, or the actual sale, lease or rental of any merchandise, service or rights or privileges at a price or with a rebate or payment or other consideration to the purchaser which is contingent upon the procurement of prospective customers procured by the purchaser, or the procurement of sales, leases or rentals of merchandise, services, rights or privileges, to other persons procured by the purchaser, is declared to be an unlawful practice rendering any obligation incurred by the buyer in connection therewith, completely void and a nullity. The rights and obligations of any contract relating to such contingent price, rebate or payment shall be interdependent and inseverable from the rights and obligations relating to the sale, lease or rental.