The number nobody in your business has worked out

Here is a short piece of arithmetic worth doing once. Take the number of people who did not turn up last month. Multiply it by what that slot would have earned. That is the number.

For most businesses it is somewhere between a good week and a month’s rent, and the reaction is always the same: it cannot be that much. It is that much, and the reason it stays invisible is that it never appears anywhere. A booking that did not happen leaves no receipt.

Most no-shows are not rudeness

A small number of people genuinely do not care. The large majority forgot, or thought it was Thursday, or meant to cancel and never got round to it. Those are three different problems and all three have the same cheap answer: tell them, before the day, in a way they can act on.

A reminder is not one message

The reminder that works is not "see you tomorrow". It is a message that gives them a way out — confirm, or move it, with one tap. People who are given an easy way to cancel do cancel, and that is the point: a cancellation at six o’clock the day before is a slot you can sell. A no-show at ten the next morning is not.

Counter-intuitively, making it easier to cancel is what fills the diary, because it converts silent losses into early warnings.

The hour after

When a cancellation does come in, the window to refill it is short and it closes while you are with someone else. A waitlist that already knows who wanted Thursday turns that into one message going out while you are still working.

When to ask for something up front

For long or expensive appointments, a deposit changes the arithmetic entirely — not because you keep the money, but because almost nobody abandons a booking they have paid against. Keep it for the slots where an empty chair genuinely hurts, and leave the quick ones alone.

What changes

Do the sum again after a month of reminders. The difference is the clearest number you will ever get out of any system, because unlike most improvements, this one you can count.