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Sean Ellis on why “a high velocity of tests” is crucial for finding product/market fit

September 11, 2025

“The best growth hacks are not things that trick people. It’s about finding where people get confused in the product today, and finding ways to make it easier and simpler for them,” The author of Hacking Growth explains. “It’s about improving the customer experience about the things that matter.”

Sean points out that most of the time the first thing you build is a guess. Sometimes your first guess is good, but usually it takes a lot of tests and experiments to figure out how to make your product more useful and less confusing. He recalls a quote from Jeff Bezos on the importance of experiments:

“Our success at Amazon is a function of how many experiments we do per year, per month, per week, per day.”

Sean has found this to be really true in practice, and the process starts with analysis. He explains:

“The first analysis I’m doing is more of a qualitative analysis of ‘Who loves the product and why do they love it?’… It’s really hard to improve something you don’t understand. Then you say, ‘Ok I have ideas to improve the situation’ and the next step is to generate some ideas. Then you prioritize which of those ideas you want to test first. Then you run the tests and analyze the results. [Growth hacking] is just that repeating process of trying a lot of ideas to figure what’s going to work and what’s not going to work. One of the most important things in growth hacking is just running a lot of tests — a high velocity of tests. I’m going to emphasize that over and over because it’s really important and nobody consistently knows what [experiment] will be the best.”

Sean continues:

“Every test you run is an opportunity to find that one big test that ultimately is a lot more successful than everything else that you do. It’s often a mistake when teams are obsessed with trying to run one perfect test and get so excited about an idea that they only want to focus on one. It’s much better to make sure that every week, we’re running at least 3-5 different tests, depending on the size of the company. You just don’t know which one’s going to be the one that ends up being super high impact and make a big difference in the growth of a business.”