How to Choose the Right Number of Stamps and Reward
The two biggest design choices on a stamp card are the threshold (how many purchases earn a reward) and the reward itself. Both have surprisingly large effects on retention.
How many stamps should the card have?
Research on loyalty programs (Kivetz et al., the "endowed progress effect") suggests cards in the 8 to 10 stamp range outperform 5-stamp cards on lifetime visits, even though the 5-card customer reaches the reward sooner. The mechanism: a longer card creates more individual visit hooks.
For coffee shops, 10 is a good default. Higher-ticket categories (lunch, salons) usually do better at 6-8.
How to write the reward text
- Be specific: "Free 12oz coffee" beats "Free drink".
- Avoid restrictions in the reward text itself. Put exclusions in the small print.
- Match what the customer would have paid for — vague rewards feel cheap.
Changing the program after customers have signed up
You can change the threshold and reward text at any time. Customers who signed up under the old program complete that program first and only see the new one after their next reward.
For loud changes (a discount becoming smaller, a free item becoming a discount) consider a broadcast push so customers aren't surprised at the counter.
Frequently asked questions
Can I run more than one program at the same time?
Each shop runs one stamp program at a time. Most shops find one well-designed card outperforms several mediocre ones.
Do customers lose progress if I change the reward?
No. Their stamp count is preserved.