From the T's&C's:

Marriott ExecuStay
Earn 2.5 points per US dollar on all qualifying charges regardless of the length of the stay at Marriott ExecuStay, where every 3 nights stayed will award members 1 night toward Elite status. As a guest, you’ll find corporate housing solutions for the business traveler in need of smartly appointed living accommodations, in the location of his or her choice. Only points, rather than miles, may be earned as a guest at ExecuStay.