I've seen this (and done this) with Hyatt infrequently and Marriott frequently as a "battlefield situation." It typically begins with me trying to check in while my wife attempts to corral our young kids that are hopped up after sitting on a plane for a few hours. The front desk agent says, "sir, perhaps you would like to have a second room - adjoining - for 50% of the rate you paid for the first room." My answer - 4 out of 4 times in the last year - "congrats on the upsell - done deal."