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Hotel.com which is owned by expedia connects to hotels via a Global Distribution System (GDS) like Sabre or Pegasus. All reasonable sized hotel's connect to one of the GDS's (there are 3-4) and travel agents and OTA's like expedia and priceline also connect to them. Getting access to one of the GDS systems takes time and costs a lot. The GDS's speak XML using the Open Travel Alliance's spec. Travel agents typically make a 10% commission on books they make. Hotels pay the commission to the TA and usually a couple of dollars per booking to the GDS. Expedia and the other big OTA's do it differently, making deals with each hotel company and charge much higher commissions.
Hotel.com which is owned by expedia connects to hotels via a Global Distribution System (GDS) like Sabre or Pegasus. All reasonable sized hotel's connect to one of the GDS's (there are 3-4) and travel agents and OTA's like expedia and priceline also connect to them. Getting access to one of the GDS systems takes time and costs a lot. The GDS's speak XML using the Open Travel Alliance's spec. Travel agents typically make a 10% commission on books they make. Hotels pay the commission to the TA and usually a couple of dollars per booking to the GDS. Expedia and the other big OTA's do it differently, making deals with each hotel company and charge much higher commissions.