Merchant Model : In this model, hotels sell rooms to OTAs in bulk at discounted or wholesale prices. The OTAs then sell them to customers at a markup price. This is the most commonly used model, and it benefits both parties. Like Expedia follows this model. Actually Expedia follows both models. Agent Model : This is a commission-based model wherein hotels give OTAs commissions based on business bought. In this model, the hotels list their services, and the OTAs don’t have to buy anything up front. This is beneficial for hotels, as it gives them the freedom to price their rooms as per the demand scenario. Booking.com follows this.