A radius is an audience

A restaurant that delivers within three kilometres does not have an audience of a city. It has a few thousand households, and it can reach all of them by Tuesday.

The dashboard will never tell it so. The platform reports a potential audience of millions, which is true of the platform and false of the kitchen. Anybody outside the radius who sees the ad cannot buy. The real audience is the people who could have the food at their door in half an hour, and in a dense part of Cairo or Jeddah that is a few streets in each direction.

So the first two days of a small operator's budget buy reach. Everything after that buys frequency. By the end of the week the same neighbours have seen the same photograph of the same burger eleven times, at a level of repetition a national brand would never permit itself and never has to, because a national brand runs out of money long before it runs out of people. The operator runs out of people on Tuesday and keeps paying.

Which changes what the ad is for. At that scale it is not discovery, and it is not persuasion. It is a reminder, standing in for the sign he cannot afford on the main road.

A reminder is only welcome if it carries something today. A dish that was not on the menu last month. A Friday. The hour the kitchen is quiet and the order arrives hot. The fact that he is open when the others have closed.

Without one of those, the budget is buying the same face at the same door for the fourth time this week, and the neighbours are learning to look past it.