2 Quotes by Everett N. McKay

One cannot not communicate. Because every behavior is a kind of communication, people who are aware of each other are constantly communicating. Any perceivable behavior, including the absence of action, has the potential to be interpreted by other people as having some meaning.

If your product solves real problems, has a simple, intuitive interaction and an appealing, easy-to-read visual design, yet people aren’t using it, chances are your product is failing to communicate at a human level.