How a Lisbon Café Put Its Stamp Card in 19 Customers' Phones in Five Days

A café in Lisbon called Calmô had the same loyalty setup as almost every café on earth: paper punch cards. And the same problems. Cards got lost, washed, forgotten in other jackets. The people who loved the café most were the ones apologizing at the counter for losing their third card.

This is what happened when they switched to a digital stamp card, with real numbers from their first weeks.

The setup: one morning, one poster

Calmô signed up for Stampish, uploaded their logo, set their reward (a free drink after ten stamps), and printed a QR poster for the counter. That was the whole project. No hardware, no app to build, no training beyond telling the team the four-digit PIN for the staff scanner.

A customer scans the poster, types their name and email, and taps Add. The card slides into Apple Wallet or Google Wallet with the café's logo and colors on it. When they order, staff scan the card's QR from any phone and tap +1 stamp. The customer's card updates on their phone in seconds, wherever they are.

The first five days

Two details from the data are worth noticing.

Transfers happened naturally. Several customers walked in with half-finished paper cards. Staff stamped their new digital card the matching number of times, and the paper era ended one pocket at a time.

The morning rush did not slow down. The whole exchange at the counter is a scan and a tap, faster than finding and punching a paper card. The line kept moving.

What surprised the owners

The banner became a channel. Calmô can publish a short message that appears on the face of every card in every customer's Wallet, within minutes. "Double stamps this Friday" reached every cardholder at once. No email open rates, no social algorithm deciding who sees it.

The card fixed real edge cases. One regular lives directly above the café and was seeing the card on his lock screen all day, so his card got switched to quiet mode: it still collects stamps but never makes a sound. Another customer thought she lost her card; her stamps were safe on the server the whole time, because the phone is just a display.

What this means if you run a café

• The wallet beats the junk drawer. Your card lives where customers already look several times a day.
• Nothing to download means people actually join. A QR scan is a much smaller ask than an app install.
• Stamps that cannot be lost protect your best customers, the ones with the most stamps at risk.
• Start with the poster by the register. One well-placed QR did all of Calmô's recruiting.

If you want the details on how the reward math works, read what your punch card reward should be. If you are weighing paper against digital, this comparison is the honest version.