The short answer
For a café, 8 to 10 stamps for a free drink is the norm. For services people buy less often, like haircuts, beauty treatments or car washes, 5 to 8 is more common. Pick a goal a typical regular can reach in about one to three months: long enough to be worth something, short enough to stay motivating.
Start from what the reward costs you
Your reward's real cost is its ingredient or time cost, not its menu price. Divide it by what a customer spends to earn it, and you get the share of revenue you're giving back.
For example, if a coffee sells for €3.50 and costs you about €0.70 to make, a free coffee after nine paid ones costs €0.70 against €31.50 of sales, around 2%. The same maths on a €25 haircut with a free cut after 5 paid ones is 20% of revenue at menu price, so services often use longer cards or partial rewards like a free beard trim.
| Card | Paid visits to earn | Spend to earn | Reward cost to you | Share given back |
|---|---|---|---|---|
| Coffee, 10th free | 9 | €31.50 | €0.70 | ≈2% |
| Coffee, 7th free | 6 | €21.00 | €0.70 | ≈3% |
| Haircut, 6th free | 5 | €125 | one chair slot | depends on capacity |
Visit frequency sets the ceiling
A card that takes a year to complete doesn't feel like a reward. Look at how often your regulars come in: a daily coffee drinker fills a 10-stamp card in two weeks, while someone who gets a haircut every five weeks needs half a year for a 5-stamp card. Match the goal to the rhythm of your business.
What the research says: the goal-gradient effect
In a well-known study of a café's coffee card (Kivetz, Urminsky and Zheng, Journal of Marketing Research, 2006), customers bought coffee more often the closer they got to their free drink: the time between purchases shrank as the card filled up. People speed up near a goal.
In practice, a card where customers can see their progress drives more visits near the end. That's one reason a visible stamp strip matters more than a points number.
What the research says: endowed progress
In another classic study (Nunes and Drèze, Journal of Consumer Research, 2006), car wash customers got one of two cards. One needed 8 stamps. The other needed 10 but came with 2 stamps already filled in, so both needed 8 more washes. The pre-stamped card was completed far more often (34% vs 19%), and faster.
The lesson: starting customers with some progress makes them more likely to finish. The simplest way to do that is to give a stamp on the day someone joins.
Common mistakes
- Setting the goal from the menu price instead of the real cost, which makes the card too long.
- Making the reward vague (“a treat”) instead of concrete (“any drink”).
- Changing the goal often. Customers notice, and it feels like moving the goalposts.
- Letting stamps be added for anything. One stamp per qualifying purchase keeps it fair.
Setting it in Eazistamp
In Eazistamp you set the stamp goal once and every card, including Apple Wallet and Google Wallet passes, lays itself out to match. You also choose the reward label and text, and a daily stamp limit per customer. Most businesses start with the number they used on paper and adjust after a month of data.