Introduction

JTBD interviews sound easy but are surprisingly tough. Here's what Commoncog learned from doing them and how it changed their business.

What's the problem it solves?

It’s hard to figure out how people actually decide to buy your product. JTBD interviews help you dig into the real reasons behind customer decisions - but doing them well is harder than it looks.

Quick Summary

JTBD (Jobs To Be Done) interviews aim to uncover the true story of how a customer chose to buy a product. But most people struggle to do them well because they’re closer to detective work than casual chatting. Cedric Chin explains that the hardest parts are helping customers remember past events clearly and spotting when they’re giving made-up answers instead of real reasons.

To get better at JTBD, practice is key. You need to warm up with mock interviews and reflect on what worked or didn’t. Commoncog learned this the hard way when early interviews didn’t yield useful results because participants were too far removed from their buying moment. They also found that pairing up during interviews and preparing small details like purchase dates ahead of time helped reduce mistakes.

A major insight from Commoncog's own JTBD project was surprising: more paying customers came from people who binge-read their site (without subscribing to the newsletter) and hit a paywalled article inside a series. This discovery led them to rethink their whole growth model and sparked experiments to make those article series easier to find. The big takeaway? Interviews gave them a clearer picture, but real change came when they turned findings into predictions and tested them with data.

Key Takeaways

• JTBD interviews are hard because customers forget details and often guess why they made decisions.
• Most beginners fail by interviewing people who bought too long ago or by not digging deep enough.
• Practicing interviews and reviewing them with teammates improves skills fast.
• The best customer insights come from noticing both what is said and how it’s said.
• Data supports interviews by showing which behaviors are common or unique.
• Discovering the right buying triggers (like a paywalled article or time-limited offer) is key to driving purchases.

What to do

• Only interview recent customers (under 6 months) when starting out.
• Always run a few practice interviews with friends before talking to real customers.
• Pair up with a teammate during interviews - two heads are better than one.
• Prepare all customer data (like purchase date) before the call.
• Focus interviews around a timeline of events, starting with “Where were you when you bought?”
• After interviews, fill out a JTBD timeline with buying triggers and struggles.
• Look for repeated patterns across interviews - these often signal big insights.
• Use findings to create specific predictions (“If we do X, we expect Y to happen.”)
• Design small experiments to test those predictions in the real world.
• Use both qualitative interviews and data together - not one or the other.

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