Quite a few businesses are incentivized to collaborate with them. Freebies can range from flight upgrades to travel insurance to tickets to special events and more, depending on your destination, the time of year you travel, and the amount you spend.
This will guarantee that you receive courteous service and a satisfactory product. They may also take charge of the finer points, like arranging a car rental so that you don't get ripped off. They must also guarantee that your trip will not be interrupted...