Nobody has ever slapped a stamp card on the bar and asked for their seventh schooner free. Yet in cafés right across Australia, "buy five, get the sixth free" is practically written into the constitution. Try running a café without one and see how long it takes for someone to ask.

I've been on both sides of the counter: cook, barista, café owner and now roaster. I've stamped more cards than I could count. And I've often wondered why coffee drinkers expect a reward when beer drinkers simply pay up and move on.

Coffee is a habit. Beer is an occasion.

Most of us buy coffee daily, often from the same place and the same person. That repetition builds a relationship. The barista knows your name and your order, down to "extra hot, half sugar, in my keep cup." A loyalty card starts to feel like a thank-you for being part of the furniture.

The pub is different. It's where you go to unwind, not where you go every morning on the way to work. Hopefully.

Bespoke service at fast-food speed

A schooner is poured the same way in every pub in the country. A coffee is made for you. Your milk, your strength, your temperature. When something is made personally, you feel personally invested. And when you're invested, you like to be recognised.

The science of the stamp card

There's real research behind this. In 2006, researchers at Columbia University studied a café loyalty program. They found customers bought coffee more often as they got closer to their free one. The nearer the finish line, the faster they ran.

That's why some cafés hand out cards with two stamps already filled in. You feel you've got a head start, and you come back sooner. It's clever. It's also a little cheeky.

From my side of the counter

These days we don't sell cups of coffee. We roast it and send it out the door. So the punch card is officially someone else's headache, and I can't say I miss it.

But I still think loyalty matters. Ours just looks different. Our coffee subscription gives regulars free shipping and freshly roasted coffee on their schedule, with no card to lose in the bottom of a handbag.

And if you're after a free beer, you'll have to take that up with your publican.