Making It Incidental
Kosh wants users to save a little every day. Asking them to open the app and move ₹20 daily would fail by the second week. But users already do something many times a day that Kosh can see: they pay for things. What if saving simply happened as a side effect of paying?
The rule
Attach the new behavior to something users already do for other reasons.
Making it incidental means designing so the target behavior happens as a by-product of an action the user already takes for their own reasons. The user never decides to do the target behavior; it rides along.
Examples:
- Round-ups: each payment is rounded up to the next ₹10 and the difference goes into savings. Pay ₹183 for groceries, and ₹7 is saved.
- Stairs in the path: a building places attractive stairs right by the entrance and the lifts around a corner, so walking up is simply the natural route.
- Step counting: a phone counts the walking you were doing anyway and turns it into visible exercise progress.
The action the user already does is the host behavior. A good host is:
- frequent — it happens as often as you want the target behavior,
- already reliable — the user does it without being asked,
- compatible — the target behavior can ride on it with no extra steps.
Making it incidental is not the same as a default. A default is decided once at a single moment. An incidental behavior repeats each time the host behavior happens, powered by the user's own daily life.
The shortcut
Find the host. List what users already do in or near the product, note how often each happens, and pick the most frequent one that can carry the target behavior with zero extra steps.
List candidate hosts
In Kosh, users make UPI payments (several a day), check their balance (a few times a week), and receive salary (monthly).
The trap is picking a host the user doesn't really perform, or adding an extra confirmation step each time. Then it is no longer incidental — it is just another task.
Drills
Answer fast — trust the rule.
Which design makes saving incidental?
In the round-up feature, what is the host behavior?
You want users to do something daily. Which host is the best candidate?
Why does an incidental design need no fresh motivation each time?
Remember
- Attach the new behavior to something users already do for other reasons.
- Shortcut: find the host — frequent, reliable, compatible, with zero extra steps.
- Trap: an extra confirmation each time turns "incidental" back into a task.