Corporate giving usually depends on a good year. A share of revenue does not. It means the commitment is the same in a slow month as in a strong one, and that anyone can check the arithmetic: order 100 litres, and 10 are accounted for elsewhere.

It also means we cannot quietly stop. The contribution is a function of sales, so the only way to reduce it is to sell less.

The MiMaji Foundation directs that volume to rural communities in Kenya, where the constraint is rarely a single delivery and almost always the infrastructure behind it — a borehole that needs servicing, a tank that needs replacing, a school with no clean supply at all.

Delivering bottled water to a village is a gesture. Keeping a source working is the useful version, so the contribution is weighted towards supply that lasts beyond the day it arrives.

A household ordering two 20L jugs a week contributes roughly 200 litres a year without doing anything beyond buying the water it already needed. An office on a standing weekly delivery contributes considerably more.

The second figure is the one worth sitting with. It is not a large number for one household. It is a large number for a city of them.

This does not solve Kenya's water problem, and we would rather say so than imply otherwise. It is one company routing a fixed share of what it sells towards the people least likely to be served by a delivery network.

What makes it worth doing is that it grows on its own terms. Every new customer in Kilimani or Kasarani raises the contribution without a board having to approve it.

There is no separate donation to make. Order water and the share is already counted. To understand how the water itself is checked, see Know Your Water.