Customers get vested in certain paradigms of computing, and those large vendors will try to keep those customers in those paradigms of computing for as long as possible. That's where you basically get the term cash cow.
Marc BenioffLearning how to interact with customers is something that anyone starting any business must master. It's an amazing opportunity to be able to learn the ropes at an established company and then employ your expertise at your own company.
Marc Benioff