Adjacent User Theory
Find growth by understanding and dogfooding the product as the next user just outside your current base.
- Difficulty
- Moderate
- Time to result
- ~months to results
- Steps
- 4
- Confidence
- 95%
A growth lens for identifying where your next users come from: not your existing power users, but the 'adjacent user' — someone who could use the product but for whom it doesn't quite work yet. In a fast-growing product the user base changes constantly, so you must continually identify who the next user is, why the product fails them, and then experience the product as them to see what's broken.
Origin
Developed by Bangaly Kaba and his team at Instagram during hypergrowth (grew ~47% in 2016), where the person using the product in February was completely different from October's user. Kaba popularized the term 'adjacent user.'
Core principles
- 01Growth comes from the users just outside your current circle, not your existing loyal base.
- 02In hypergrowth, who your users are changes every few months — you must keep re-identifying them.
- 03Declining cohort curves with no product change often signal you've reached a new, less-savvy adjacent user.
- 04A power user's history makes their experience nothing like a brand-new user's — a fresh account reveals the real gaps.
- 05It's mandatory for hypergrowth, and still valuable for stalled products trying to capture more of an audience.
How to run it
- 1
Deeply understand who uses the product today and why
Map the persona, motivations, and jobs of your current users so you have a baseline to compare against.
- 2
Identify the next adjacent user
Name who could be using the product but for whom it currently doesn't work — often less tech-savvy, in a new market, or with different needs than today's user.
Pro tip Watch for cohort curves that decline three-to-six months out even though nothing in the product changed — that's the adjacent user arriving.
Watch out Don't assume new users behave like your current base — the phone they use, their market, and their understanding all differ.
- 3
Become the adjacent user
Create a fresh account and use the product as they would, watch them use it, talk to them, and even visit them to see what they do in real time. Combine with user research.
Pro tip A brand-new Gmail + YouTube account is a 'completely different and significantly worse' experience than a power user's — that gap is your opportunity list.
- 4
Build for the jobs the adjacent user actually has
Enable the specific functionality and jobs-to-be-done the adjacent user needs to become an adopter, rather than optimizing further for existing power users.
In the wild
The original Instacart user might have been an office admin buying for team happy hours; the next adjacent user was a parent of three or four depending on the service, and later a single person in New York using it for convenience. What each optimized for and how they used the product changed fundamentally.
→ Recognizing these shifts meant building different experiences and jobs for each rather than assuming one persona.
Instagram's registration flow would convert at an insanely high percent, then drop ~15% three months later — not because anything broke, but because they'd broken into new markets like India and the Philippines where users' tech familiarity and phones differed.
→ Understanding the adjacent user explained the decline and redirected the work.
Common mistakes
Judging the product only as a power user
Your years of history and informed knowledge make your experience unrepresentative; you'll miss obvious opportunities the adjacent user hits immediately.
Reading a cohort decline as breakage
Assuming a dropping conversion or retention curve means something broke, when it actually means a new, different adjacent user has arrived.
Is it for you?
Best for
Growth PMs at hypergrowth or scaling products who need to sustain acquisition beyond their current user base.
Not ideal for
A product with a fixed, saturated audience focused purely on share-of-wallet — still useful, but less essential than for hypergrowth.
From the transcript
“who is the user who could be using this product but for some reason it doesn't work for them right and understanding who that adjacent…”
“you have to be them you have to watch how they use the product you have to talk to them and you have to visit…”
“if you were to go and create a new Gmail account and and look at YouTube today I guarantee you it's a completely different and…”
“it's essential it's mandatory for hyper growth”
From the episode
Unorthodox frameworks for growing your product, career, and impact
Bangaly Kaba (YouTube, Instagram, Facebook, Instacart)