Talking about other businesses is, essentially, talking business. Other businesses could be friends, foes, inspirations or anything else. A simple topic, yet such a deep one. Some questions you could ask are:
What can businesses do to succeed?
What is your idea of a business?
What businesses are successful in your country/industry? Why?
Why do you think some businesses fail?
Business is a combination of war and sport. Do you agree? Why/why not?