They don't. We do. It comes out of our hide. Online travel agencies charge high commissions to the hotels.
Booking.com charges 20%. Hotels.com, Travelocity, Expedia, Priceline and others charge between 22 and 25%. And that's if you have a franchise affiliation and let your franchise organization negotiate it for you.

And those are the ones where you -- the consumer -- don't get that much of a bargain. A contract between a hotel and an online travel agency provides for 'rate parity': each OTA wants a promise from the hotel that the rate provided to it is the lowest publicly available rate, and provides stiff penalties to the hotel if a lower rate is found elsewhere. Likewise, every franchise organization offers some version of a 'Best Internet Rate Guarantee', and holds their franchisees to it. (I should have listened to my dad and made it my goal to go to Duke Law when I was a kid: I smell a lucrative opportunity here for a mass tort lawyer to file a class action suit on antitrust and price fixing claims . . .). Since the 'lowest publicly available rate'/'Best Internet Rate' can only be one number, and that number can't be any lower and still be either the 'lowest publicly available rate'/'Best Internet Rate' ; what you pay on any of those websites is going to be very close to the hotel's 'Best Available Rate', the rack rate (see Michael Forrest Jones' answer to What is and why do hotels have a rack rate? )
Booking.com charges 20%. Hotels.com, Travelocity, Expedia, Priceline and others charge between 22 and 25%. And that's if you have a franchise affiliation and let your franchise organization negotiate it for you.

And those are the ones where you -- the consumer -- don't get that much of a bargain. A contract between a hotel and an online travel agency provides for 'rate parity': each OTA wants a promise from the hotel that the rate provided to it is the lowest publicly available rate, and provides stiff penalties to the hotel if a lower rate is found elsewhere. Likewise, every franchise organization offers some version of a 'Best Internet Rate Guarantee', and holds their franchisees to it. (I should have listened to my dad and made it my goal to go to Duke Law when I was a kid: I smell a lucrative opportunity here for a mass tort lawyer to file a class action suit on antitrust and price fixing claims . . .). Since the 'lowest publicly available rate'/'Best Internet Rate' can only be one number, and that number can't be any lower and still be either the 'lowest publicly available rate'/'Best Internet Rate' ; what you pay on any of those websites is going to be very close to the hotel's 'Best Available Rate', the rack rate (see Michael Forrest Jones' answer to What is and why do hotels have a rack rate? )
