Sunk Cost Effect
How users stay stuck in subpar workflows just to justify past effort, and what you can do about it.
Definition
The Sunk Cost Effect is the tendency for people to keep investing time, money, or effort into something simply because they’ve already spent resources on it, even when better options exist.
In UX, this manifests when users stick with a product they’ve heavily customized or learned, not because it’s the best tool, but to justify past investment. It’s rooted in behavioral economics: humans hate the idea of wasted effort.
Understanding this principle is fundamental in human-computer interaction because it shapes retention, churn, and user satisfaction. Users may tolerate friction or pay more than they should just to avoid “wasting” their initial outlay.
By recognizing where sunk costs drive behavior, you can design experiences that respect users’ past investments while gently guiding them to better choices or more value, rather than trapping them in loyalty by default.
Real world example
Think about WordPress users who spend hours customizing themes and plugins. Even when a more intuitive CMS exists, they stick with WordPress because they dread losing all that configuration work, classic sunk cost behavior at play.
Real world example
You’ll see the sunk cost effect everywhere: in user onboarding flows where early friction is forgiven because users invested in completing setup; on crowded feature dashboards where habit keeps people from migrating to simpler tools; and during cancellation processes where long, customized histories make users pause before pulling the plug. Recognizing these hotspots helps you decide whether to smooth pain points or offer seamless exits.
What are the key benefits?
Everything you need to make smarter growth decisions, without the guesswork or wasted time.
Surface users’ past investments as value (e.g., “You’ve already published 50 posts, keep building on that!”).
Offer guided upgrades that honor previous work (e.g., auto-migrate settings to pro plans).
Use subtle reminders of effort spent to nudge feature adoption (e.g., “You’ve spent 10 hours editing, save time with our new editor”).
What are the key benefits?
Everything you need to make smarter growth decisions, without the guesswork or wasted time.
Don’t punish users for switching, avoid data-loss barriers that exploit sunk costs.
Don’t hide exit options behind convoluted steps just to trap users.
Don’t overemphasize initial setup investment and then deliver poor ongoing value.
Frequently asked questions
Growth co-pilot turns your toughest product questions into clear, data-backed recommendations you can act on immediately.
How can I tell if users are staying because of sunk costs or because they love my product?
Segment feedback, ask both new and long-time users why they stick around. If long-timers cite past effort over feature love, you’ve uncovered sunk-cost-driven retention.
Is leveraging sunk costs unethical?
Not if you’re honest. Acknowledge past investment and then genuinely improve their experience. Manipulating users without adding value crosses the line.
How do I reduce churn if users are trapped by sunk costs?
Focus on genuine value: streamline post-onboarding success, surface new benefits, and make exiting painless if they want out, trust builds loyalty beyond sunk costs.
Can sunk cost effect backfire?
Absolutely. If users feel trapped, they’ll churn angrily or spread negative word-of-mouth. Always couple sunk-cost triggers with clear value delivery.
What metrics signal a sunk cost problem?
Look for high time-on-platform but low feature engagement and elevated cancellation hesitations, signs users endure friction to justify previous effort.
Don’t Let Sunk Costs Trap You
Run your onboarding flow through the CrackGrowth diagnostic to pinpoint where sunk-cost biases are inflating your retention metrics, and turn wasted effort into real product love.