Large and small companies in every industry continually experiment with different ways of advertising, promoting, and selling their products and services. And here is the rule: Whatever method of marketing and sales you're using today will, sooner or later, stop working. Sometimes it will stop working for reasons you know, and sometimes it will be for reasons you don't know. In either case, your methods of marketing and sales will eventually stop working, and you'll have to develop new sales, marketing and advertising approaches, offerings, and strategies.