Friction is resistance to motion or change. In physics it opposes movement; in systems it opposes flow — of users, decisions, money, or information. Friction slows things down and consumes energy. It can be intentional (security checks, approval gates, verification) or unintentional (poor UX, bureaucracy, legacy process). The strategic question is whether friction serves a purpose or is pure cost. Friction that protects (e.g. confirm before delete) or aligns (e.g. approval for large spend) can be valuable. Friction that has no benefit — extra clicks, redundant steps, slow systems — is waste. The discipline is mapping where friction exists, classifying it, and removing the bad while preserving or designing the good.
Friction often appears at boundaries: signup, checkout, onboarding, approval, handoff. Each boundary can have too much friction (abandonment, delay) or too little (fraud, error, misalignment). Reducing friction at the right boundaries accelerates growth and execution; reducing it at the wrong ones increases risk. The best operators know which friction to cut and which to keep or add. One-click purchase reduces friction and increases conversion; one-click nuclear launch would be catastrophic. The context determines the right level.
Friction is also a competitive lever. Your product can win by having less friction than alternatives (faster signup, fewer steps) or by having friction that competitors don't (e.g. curation, quality bar) that signals value. The model doesn't say "minimise all friction"; it says "understand friction, remove what doesn't serve, and use what does."
Section 2
How to See It
Friction reveals itself when desired actions are slow, require many steps, or drop off. Look for drop-off in funnels, delay in approvals, and user complaints about "too many steps." The inverse: when something is suspiciously easy and leads to error or abuse, there may be too little friction.
Business
You're seeing Friction when a sales process has seven approval steps and each takes a week. Deals close slowly; some die in the pipeline. The friction may be intentional (governance) or accidental (legacy process). The question is whether each step adds value.
Technology
You're seeing Friction when signup requires email verification, then profile completion, then payment — and 60% drop at each step. Friction is the resistance to completing the flow. Reducing steps or deferring non-critical asks can increase conversion.
Investing
You're seeing Friction when redeeming from a fund takes 30 days and multiple forms. The friction protects the fund but annoys the investor. Competitive funds with lower friction may attract flows.
Markets
You're seeing Friction when switching banks or brokers is so cumbersome that customers stay even when they're unhappy. Friction is the switching cost. Incumbents benefit; new entrants must overcome it.
Section 3
How to Use It
Decision filter
"Map friction in key flows — signup, purchase, decision, handoff. For each point of resistance, ask: does this friction serve a purpose (safety, alignment, quality)? If yes, keep or refine it. If no, remove it."
As a founder
Audit the main user and operational flows. Where do people drop off or slow down? Remove friction that has no benefit. Add or keep friction where it prevents error, fraud, or misalignment. Design friction intentionally.
As an investor
Assess portfolio companies for friction in growth and execution. High friction in signup or sales lengthens cycles and depresses conversion. The best companies have low friction where it doesn't matter and appropriate friction where it does.
As a decision-maker
Before adding a step, approval, or check, ask what it protects. If the answer is vague, the friction may be habit, not design. Before removing a step, ask what failure mode it prevented.
Common misapplication: Treating all friction as bad. Some friction is valuable — it filters, verifies, or aligns. The goal is not zero friction; it's the right friction in the right place.
Second misapplication: Optimising one step and ignoring the flow. Reducing friction at signup but leaving a terrible onboarding can increase signups and churn. Map the full flow; optimise for the outcome.
Bezos obsessed over reducing friction in purchase and delivery — one-click ordering, fast shipping, easy returns. Friction removal was a growth lever. He also added friction where it mattered: bar raisers in hiring, six-page memos for big decisions.
Netflix reduced friction in streaming: no late fees, no physical return, simple signup and cancel. The friction of Blockbuster was eliminated. Hastings framed the business as winning on convenience and low friction.
Section 6
Visual Explanation
Friction — Resistance along a flow. Too much: drop-off and delay. Too little: error or misuse. Right amount: flow with guardrails.
Section 7
Connected Models
Reinforces
Activation Energy
Activation energy is the minimum energy required to start an action. High activation energy means high friction to get started; reducing friction lowers activation energy and increases starts.
Reinforces
Switching Costs
Switching costs are friction that keeps customers from leaving. High switching costs are friction for the competitor and low friction for you (retention).
Leads-to
Flywheel
A flywheel accelerates when friction is low: each turn is easier. Friction in the loop slows the flywheel.
Reinforces
Friction & Viscosity
Friction & Viscosity (physical) is resistance to flow. The mental model extends the metaphor to process and UX.
Tension
Law of Diminishing Returns
Removing friction has diminishing returns: the first unnecessary step you remove may have big impact; the tenth may have little.
Section 8
One Key Quote
"Don't make me think."
— Steve Krug, Don't Make Me Think (2000)
Krug's mantra for web usability is a friction argument: every moment of confusion or extra click is friction. Reducing unnecessary thinking and steps reduces friction and increases completion.
Section 9
Analyst's Take
Faster Than Normal — Editorial View
Map the flow, then the friction. List the steps in your key flows. At each step, ask: is this friction necessary? If it prevents error or aligns incentives, keep it. If it's legacy or habit, challenge it.
Friction as filter. Not all friction should be minimised. Applications, hiring, partnerships — friction can filter for seriousness and fit. Put friction where it selects for what you want and remove it where it just annoys.
Measure drop-off. Friction shows up as drop-off and delay. The steps with the biggest drop-off or the longest delay are friction hotspots. Fix those first.
Section 10
Test Yourself
Is this mental model at work here?
Scenario 1
A checkout flow has 5 steps: cart, shipping, payment, review, confirm. 40% of users abandon between cart and confirm. The team removes the separate review step and combines it with confirm.
Eyal discusses reducing friction in habit formation. Lower friction to the desired action increases the chance the habit forms.
Summary: Friction is resistance to flow. Map it in key flows; remove friction that has no purpose; keep or add friction that protects or filters. Use friction deliberately.
Further Reading: For UX and conversion, see Krug and growth literature. For the physics metaphor, see Friction & Viscosity and activation energy.
Leads-to
Minimum Effective Dose
Minimum effective dose is the smallest intervention that works. In friction terms: the minimum friction (steps, checks) that achieves the goal.
