The messy middle is a term Google uses to describe what happens between the moment someone realises they need something and the moment they decide what to buy. It is not a straight line. People bounce between exploring options and evaluating them, often looping back and forth until they feel ready to choose.
For brands, this means it is not enough to only show up at the start or the end of the journey. You need to be present in the middle too, giving people reasons to choose you over the competition. That might be through helpful content, strong reviews, competitive pricing, or simply being visible at the right time.