They are constantly compared to one another. They are both essential to your business. They are (in boring textbook terms) an integral part of your marketing mix. They are public relations and advertising.
In ancient Greece, message couriers were used to send news from one part of the country to the other. In fact, the word marathon is inspired by a Greek legend about a soldier named Pheidippides who ran 25 miles from the town of Marathon to Athens to tell officials that Athenians had saved Greece from the Persian forces.
A dozen years ago the chairman of Bloomingdales stood in front of a customer acquisition panel and said without blinking: “The most important people are those that go up in the elevator at 9 and leave at around 6.”