(1) Any telecommunications tariff filing that makes a promotional offering becomes effective on the later of the effective date stated in the tariff or the date it is filed with the commission.

(2) For purposes of this section, a promotional offering is a telecommunications tariff that, for a period of up to ninety days, waives or reduces charges or conditions of service for existing or new subscribers for the purpose of retaining or increasing the number of customers who subscribe to or use a service.