As of yesterday, five big resorts, including the Homestead in Virginia, Barton Creek in Austin, Tex., and La Costa in Carlsbad, Calif., shed their independence and joined Omni’s Resort Collection. Business travelers encounter this all the time: A hotel they’d been staying at for years suddenly changes brands. What used to be a Westin is now a Wyndham (WYN). A Hyatt (H) becomes, almost overnight, a Marriott (MAR).

Brand changes are often the only visible result of what is usually a three-way transaction that defines how hotels are owned and managed today. Scratch the marble-and-brass surface of today’s hotels, and things are trickier than they may appear.