A list people can finish

Ask anyone to name the days of the week and they will do it without thinking, in order, and stop at seven.

Ask the same person to name every flavour a snack brand makes and they will manage three, in no particular order, and then wonder aloud whether there is a fourth.

The difference is not the number. It is that the week has an end and a sequence. You know when you have finished it. You know what comes after Tuesday. A list like that can be held whole in the head, which is rare and valuable, and almost nothing a business makes has both properties.

Most ranges grow by addition. A new size because one shop asked, a new colour because a competitor had one, a limited edition that was never retired. Each made sense at the time. Together they form a pile, not a set. Nobody can recite it, so nobody can choose from it with any confidence, and the shopper in a Kuwait supermarket aisle picks the one she bought last time, because that is the only one she is sure exists.

The ranges people do remember tend to be short and closed, and their order is not decoration. Small, medium, large. Mild, medium, hot. One to five. Nobody invented those sequences. They were already in the thing itself, and the maker simply noticed them and stopped adding.

That is the hard part. Finding an order that is real takes thought, and closing the list takes nerve, because every new item feels like more choice for the customer.

But more items only make a longer list. People can only finish a list that ends.