- Customers don't buy products; they hire them to do a job (Christensen).
- The four forces of switching explain what drives adoption and inertia.
- JTBD beats personas for framing competition, but can over-claim, so use it where it fits.
The Jobs to be Done framework, as Clayton Christensen tells it in his 2016 Harvard Business Review piece, starts with a fast-food chain trying to sell more milkshakes. The marketing team had already segmented the customer base by age, income, family status, and personality type. They'd asked thousands of customers what would make the milkshake better (thicker, fruitier, chunkier) and improved the product against the feedback. Nothing moved. The lever was missing because the question was missing.
Then a researcher spent a day in the restaurant watching who actually bought milkshakes, when, and what happened next. The surprise was the morning. Forty percent of milkshakes were sold before eight a.m. — to solo commuters, who drove off the lot with the shake in the cup holder. None of them ordered fries, none of them ordered anything else. Interviews followed. The job, it turned out, wasn't feed me a treat. The job was make my forty-minute commute less boring, fill me up so I don't get hungry at ten, and keep my hands clean while I'm driving. The competition wasn't the McDonald's milkshake. It was a bagel (crumbly, two hands), a banana (gone in three bites), a coffee (no calories), or skipping breakfast altogether. That is Jobs to be Done.
The framework, simply.
Christensen's claim is structural. People don't buy products. They hire products to make progress in a specific situation. The product is the means; the progress is the end. If you understand the job in enough detail, you understand who you're really competing with, what features actually matter, and why someone switches.
The job statement template that's settled into the canon is straightforward: when [situation], I want to [motivation] so that I can [expected outcome]. The milkshake job becomes: when I'm commuting alone in the morning and dreading a forty-minute drive, I want to keep my hands and mind occupied with something filling so that I can arrive at work not hungry and not bored. Compare that to a persona ("married 35-year-old commuter, 60k household income, two kids"). The persona tells you who they are. The job tells you what they're doing and why, which is what predicts what they'll buy.
The four forces of switching.
The most usable extension of JTBD comes from Bob Moesta, who co-developed the framework with Christensen and has spent twenty years interviewing customers about moments of switching. His Forces of Progress model says that every switch, from old product to new, is governed by four forces: two pushing toward the new product and two pulling back.
Push of the current situation. What's failing about today? The pain that's built up against the existing solution. Without push, the customer isn't actually shopping. They're just looking. Push is the energy that makes them ready to switch.
Pull of the new product. What does the new solution promise? The imagined progress. This is where most marketing teams concentrate — features, benefits, the better future. Pull matters, but it's only half the equation.
Anxiety of the new. Will it work? Will it integrate? Will I look stupid for choosing it if it fails? Anxiety is the soft block — it's the reason most demos go great and most deals stall. Most teams under-invest here because anxiety isn't logical and isn't on the feature list.
Habit of the old. Switching is effort. The current setup already works, partly. Migrating data is annoying. Retraining people is annoying. The old product, however flawed, is the path of least resistance. Habit kills more switches than features ever convert.
The implication for product strategy is significant. Most teams compete on Pull, building a better version of the same feature set. The Jobs frame reveals that the competitive lever is often Anxiety reduction (proof, guarantees, trial paths, integration tooling) or Habit subversion (migration tools, behavioural triggers, switching incentives). The product that wins isn't always the best one. It's the one that moves the equation.
Switch interviews — the actual research.
Where JTBD gets methodological is in the switch interview. Find a customer who recently changed from one product to yours (or anywhere else). Walk them backward through the timeline. When did they first realise the old solution wasn't working? What were they thinking? What did they try first? What made them shortlist? What nearly stopped them buying? What did they have to do internally to make the switch happen?
Done well, switch interviews surface the four forces in the user's own words. They're harder than they look. Most people rationalise after the fact, claim they bought because of features, and skip over the anxiety. A good interviewer keeps anchoring back to what were you actually thinking, at the moment you decided. Twenty interviews of that quality, run across recent switchers and recent non-switchers, will tell you more about your market than a year of feature feedback.
Where JTBD beats personas.
Personas describe people. Jobs describe situations. The same person hires different products for different jobs across their day. A senior engineer hires Slack for quick coordination, Notion for thinking out loud, and email for paper-trail compliance. The persona is constant, the job switches by context. Persona-led product work assumes the persona drives the decision. JTBD-led product work assumes the situation drives the decision. In practice, situations are far more predictive of behaviour than demographics.
That doesn't make personas useless. They're useful as a communication shorthand and for design empathy. But if you're making prioritisation calls about which problem to solve next, JTBD is the sharper lens. The question isn't "what does the persona need?" It's "what job, in what situation, is currently going badly enough that someone would switch?"
Where JTBD over-claims.
JTBD is a lens, not a methodology. The community sometimes oversells it as the complete operating system for product, which it isn't. It doesn't tell you how to build, how to scope, how to size, or how to run a team. It tells you how to frame demand. Pair it with a delivery method (Lean, dual-track agile, whatever fits) and a pricing model and a roadmap discipline. JTBD is one piece of the picture, not the whole one.
It's also weaker for new-to-the-world categories where customers can't articulate the job yet because they've never had a product like yours. JTBD reveals switching from an existing alternative; it's less useful when the alternative is "do nothing" or "didn't realise this was possible". For genuine zero-to-one work, you need first-principles problem-discovery alongside JTBD, not instead of it.
How we use this at Product Pieces.
When a product team is stuck on prioritisation (three roadmap items, all of them defensible, no clear signal), we run a JTBD pass on the recent quarter's wins and losses. Switch interviews with five recent customers who chose us. Switch interviews with three recent prospects who chose someone else. The pattern that emerges almost always changes the roadmap. Sometimes the right next bet isn't a new feature; it's an anxiety-reduction asset (a guarantee, a migration tool, a sandbox) or a habit-breaker (a trial path that gets the user past the cost of switching). The Jobs frame tells you which lever is actually short.
If your roadmap is full of features and your sales cycle is lengthening, the issue is rarely product fit. It's almost always anxiety. Name the four forces, weight them honestly, and the next bet usually picks itself.
Next issue: N°30 — OKRs. The discipline of saying no.