What is consumer insight?

Answer 1

Consumer insight is a flash of understanding on the part of a marketer regarding an unidentified or unmet need in the marketplace, or a new/better way to satisfy an existing need.

It is NOT about a product or service, as Mike suggests. It's about a consumer need that isn't being met as well as it could be. The marketer's challenge, having recognized the insight, is to find a way to capitalize on the thinking that identified the need. That could lead to a product or service, of course, but the insight is independent of the solution.