A zero-click search is one the user never leaves: the answer is delivered right there. In a featured snippet, a knowledge panel, or now an AI Overview, so there's no click to a website. With AI answers, zero-click has gone from common to dominant for informational queries.
This is the strategic shift behind GEO. If users increasingly don't click, then the goal can't only be "rank a link to earn a visit." It has to also be being the source named and cited inside the answer: because that's where the brand impression (and the trust) now forms, click or no click.
It reframes how you measure success, too: alongside clicks and traffic, you track presence and citations in the answers themselves. Being the cited authority in a zero-click answer can shape a buyer's shortlist even when no visit shows up in your analytics. Part of why AI visibility needs its own measurement, not just web traffic.