How does a grocery or food store in Saudi Arabia get repeat customers?

By reaching the customer at the moment the first purchase runs out, through a channel that does not charge per message. Almost every store has the timing data and spends the reach budget anyway.

The mechanics of a second order

Work out the median gap between first and second order. Whatever that number is, the reminder belongs slightly before it — after it, the customer has already solved the problem somewhere else.

Winning a customer costs money and selling to them again costs almost nothing, and most budgets are spent as though the reverse were true. For a grocery or food store in Saudi Arabia, the answer turns on one thing in particular: Grocery margins are thin and baskets are large, so the whole model lives or dies on delivery cost per order.

What is different about Saudi Arabia

Saudi Arabia is the largest ecommerce market in the region by some distance, and the most phone-dominated.

Cash on delivery remains common in Saudi Arabia, which changes the economics of every refused delivery.

What is different about a grocery or food store

Discounting to grow trains people to wait for the discount. It works once.

Where a mobile app comes into it

Weekly reordering is the behaviour, and an app that remembers the last basket removes most of the work.