Hotels.com (Expedia) also has an option to pay the hotel directly. They used to require paying Expedia, and then Expedia pays the hotel, and I am guessing it was to expedite receipt of commissions (since they receive cash immediately and pay hotel the same cash minus commission at a later date).

However, I think the integrations and payment terms with the major hotel brands have gotten good enough that Expedia now prefers to be paid a commission by the hotel. This benefits Expedia as they are no longer wasting money dealing with chargebacks and card processing fees.

FYI, typically, a hotel franchisee will pay 10% to 15% to the hotel brand franchisor (Hilton/marriott/etc), and if the guest uses a travel agent like Expedia or Booking or any of the corporate travel ones, another 15% or more to the travel agent, and then the 3% to the payment processors. So for a guest who reserved via travel agent at a franchised hotel, ~30% of the room rate right off the top will not make it to the hotel itself.

And that is excluding the typical 10% to 20% sales tax the guest pays the government on top of the room rate!