Since the beginning of time in the travel industry, there has been a need for content aggregators of some description. It has never made any sense for your Mom and Pop travel agent on Main Street (or the High Street depending on where you are reading this) to have relationships with every airline, every hotel chain and every rental car agency in the world in order to fulfill the needs of their customers.
And hence, the original Global Distribution Systems (GDSs) were born. (This is actually ignoring the fact that originally GDSs were just automated booking systems for individual airlines (such as Sabre and AA) but we'll gloss over that for now.)
