The answer is a stamp card or a point card.

As you can see, this is a card.

The size is about calling card.

This is a kind of service that we can get some points when we buy things at a shop.

When we pay at a cashier, we pass it to a clerk.

He or she stamps the card or gives us a sticker as a token for the points we get.

For example, if we buy a roll of bread at a bakery, we can get 1 point, and when we collect 20 points, we can exchange the points for our favorite bread.

This service is adopted not only at a bakery but also at a general store and so on.

We can get discount tickets for the points we collect in many shops.

Incidentally, some shops set an expiration date for the points they give to us

So we go shopping at a same shop again and again to collect many points within a limited time.

That is the point!