What is a brochure? An ad? A radio commercial? A website? You get 5 points if you said they’re all marketing communications channels. But they’re also something more.
You can’t be everywhere, and that includes everywhere your prospective customers are. So you develop materials such as ads and brochures to stand in for you. In essence, they’re actually salespeople for your organization, conveying messages when you can’t be there to do it.