Answer:
driving force
Step-by-step explanation:
Customers are turning into spoiled brats, their demands are constantly evolving because their expectations of what they consider a good service is always rising. Customers will appreciate a better service, but they get used to it very fast and then they start to demand for even better services.
Social media is making things even more difficult since any complain about a perceived bad service is immediately posted and it reaches thousands of people. In an extremely connected world, any better service offered by a company must be copied or improved immediately by its competitors.