Decide
Earned perk
Effort: Medium
What to notice
Finishing a short task flips over a card with a perk.
How to build it
- Make the task about understanding the product.
- Do not oversell the perk beforehand; reveal it afterward.
- Print the conditions and expiry on the card.
Measure
- Main metric
- Perk redemption rate
- Guardrail
- Share who sign up for the perk and cancel right away
When it backfires
Purchase-linked draws fall under Japan’s premium caps.
Theory behind it
Overjustification effect
Adding contingent rewards to something people already enjoy can make them stop doing it once rewards end.
Contested
Goal-setting theory
Specific, challenging goals lead to better performance than "do your best."
Well supported
Japan’s premium regulations
In Japan, prizes tied to a purchase are capped by the Act against Unjustifiable Premiums and Misleading Representations.
Law and official guidance
Playable demos
Try the same mechanism in a playable demo.