Expository essays and business communication are similar in the way that they both use facts to explain an idea or present information. Unlike expository essays you can be biased in business communications. Management usually wants feedback about how you feel and what is going on in your aspect of the business. Facts are the main part of an expository essay. They are being used to support your thesis. For an expository essay opinion plays a small part because the it is supposed to be presenting a concept, and a concept can in someone's opinion be used to improve upon something.