Just for the disappointed like myself who will earned nothing this summer with Marriott and will likely earn nothing this fall either now that they appear to have stopped offering a Free Certs option:
Both Choice Hotels and also the IHG (Holiday Inn) chain have picked up the slack and are offering the free cert after two paid stays. While I love my Marriott hotels and prefer staying at them, this total disregard for those of us who can't achieve the number of nights needed to rack up the points has opened me up to going elsewhere.