The three tiers
Must-have
Table stakes. Causes dissatisfaction if absent, no delight if present. Users expect this. They won’t thank you for it, but they’ll leave without it. Examples: Basic authentication, terms of service page, data export, error messages.Incremental
More is better, each improvement adds proportional value. The user notices and appreciates each step up, but there’s no surprise. Examples: Faster load times, more storage, better search results, self-serve billing.Delighter
Unexpected and disproportionately satisfying. Users didn’t know they wanted this. When it lands, it generates word-of-mouth and loyalty. Examples: AI-assisted planning, proactive coaching, one-click import from existing tools.The car window example
The classic Kano illustration: car windows.- Must-have: The window opens and closes (manual crank)
- Incremental: Power windows (each car gets them, each is a step up)
- Delighter: Auto-close on rain detection (nobody expected it, everyone loves it)
Why it matters for planning
A healthy product has a mix of all three tiers:- Early stage: Cover must-haves first, then sprinkle delighters to differentiate. Skip incremental. You don’t have enough users for linear improvements to matter.
- Growth stage: Backfill incremental improvements. Your must-haves work, your delighters attracted users, now the incremental work retains them.
- Mature stage: Must-haves are commoditized, incremental is the baseline. New delighters are your competitive edge.

