1. Customers speed up as they get closer to the reward
Researchers from Columbia University (Kivetz, Urminsky and Zheng, Journal of Marketing Research, 2006) followed a café's "buy 10 coffees, get 1 free" card. Customers bought coffee more often the closer they got to their free one. The last few stamps came faster than the first few.
They also gave some customers a 12-stamp card with 2 stamps already filled in, so the same 10 purchases were still needed. Those customers finished in a median of 10 days, against 15 days for customers on a plain 10-stamp card.
What it means for you: make the reward reachable. Choose a number of stamps your customers can finish in a few months: a daily coffee drinker can reach 10 quickly, but a customer who has a haircut once a month needs a shorter card, such as "every 6th cut free". And show progress clearly, so customers can see how close they are.
2. A head start nearly doubles the number who finish
In a car wash study (Nunes and Drèze, Journal of Consumer Research, 2006), 300 customers received one of two loyalty cards. Both needed 8 paid washes for a free one. One card had 8 empty spaces. The other had 10 spaces with 2 already stamped.
Nine months later, 34% of customers with the pre-stamped card had earned their free wash, against 19% with the blank card. Same effort, same reward, nearly twice as many finishers. The researchers called it the endowed progress effect: people are more motivated to finish something they feel they've already started.
What it means for you: don't start new customers on zero. Give one or two welcome stamps when they join. In Komweer this is the "welcome bonus stamps" setting on your card.
3. People come back where they're known
This one is our view rather than a study. A regular who is greeted by name, or asked "the usual?", feels recognised, and that's a reason to come back that no discount can buy. A digital card helps you get there: you can see who your regulars are, how often they visit, when they last came in, and when their birthday is.
Why a digital card helps these effects work
- Nobody loses their progress. A paper card left in another wallet means starting over, and the head start is gone. A digital card lives on the customer's phone.
- Progress is always visible. Customers see exactly how many stamps they have and how many are left.
- Rewards don't quietly expire. Komweer emails customers a week before a reward expires, so they come back to use it.
- Stamps can't be faked. The counter code changes every 25 seconds and works once, or your staff scan the customer's card, so a photo of the code earns nothing.
How to set up a card that customers finish
- Pick a reward your customers actually want.
- Choose a number of stamps they can reach in a few months.
- Give 1 or 2 welcome stamps.
- Set a daily limit and a waiting time between stamps.
- Add a reward expiry date, so rewards get used. Komweer reminds customers before it runs out.