Data point from today, Hampton Inn and Suites in Spring, TX. Checked app yesterday and had a reservation for 2Q room. Tried check in and offered upgrade to 1K "suite" (larger room with sofa bed, wet bar, etc) for $15. Backed out. Checked again at 5 am this morning to the same result. By 9am my res was upgraded to the suite for free. Checked in on the app. Had a personalized letter with water and a snack in the room on arrival. (I didn't need 2Q and noted so in the res)