What Is the Sean Ellis Test

What does the Sean Ellis test mean?

The Sean Ellis test is a product-market fit survey built around one question: how would you feel if you could no longer use this product, with answer choices of very disappointed, somewhat disappointed, and not disappointed. Per Learning Loop's summary of the methodology, Sean Ellis, who led early growth work at Dropbox, LogMeIn, and Eventbrite, arrived at a 40 percent threshold by benchmarking the survey across nearly a hundred startups: companies where at least 40 percent of users answered very disappointed almost always went on to see strong, sustainable traction, while companies below that mark almost always struggled to grow. That correlation, not a theoretical argument, is why the 40 percent line became the standard benchmark teams still cite today.

Why the Sean Ellis test matters for product managers

Builders Camp's Product MBA certification quiz asks directly what the Sean Ellis Test is used for, and the correct answer defines it precisely as asking users how they would feel losing the product, with very disappointed responses indicating product-market fit. That precision matters because the test is easy to run badly: surveying only the most engaged power users, or wording the question loosely, inflates the very disappointed percentage and gives a team false confidence in fit it has not actually earned across its broader user base. A survey run only on power users tells a team how its best customers feel, not whether the broader market is actually pulling the product forward.

Sean Ellis test example

A team running the survey across its full active user base, not just its most engaged accounts, gets 34 percent answering very disappointed, just under the 40 percent benchmark. Rather than treat that as a failed test, Builders Camp's own material on product-market fit treats the segmented result as more useful: cutting the same data by customer type shows one segment at 52 percent very disappointed and another at 18 percent, which tells the team exactly where real fit already exists and where the product still has not landed, a much more actionable answer than one blended number. The team can now double down on the strong segment while treating the weak one as a separate discovery problem rather than a shared failure.

How Builders Camp teaches the Sean Ellis test

Product Strategy, a 2 week bootcamp with 4 live sessions and 8 microlessons taught by Andre Albuquerque, and the Product MBA's Measuring Success module both test the Sean Ellis threshold directly in their certification quizzes alongside Net Promoter Score. Product Manager Foundations covers the discovery skills that decide which segment to survey in the first place, with certification requiring a 70 percent pass mark on the quiz. See the Product Strategy bootcamp for the full curriculum.