Answer:
data mining
Explanation:
In business, Data mining is the act of obtaining information about customer's behavior that might be use for the company's benefit.
On most cases, Data mining is used to predict the behavior of a certain group of customers. By creating this prediction, the company could create a product or marketing strategy that can efficiently target that group.
in the excerpt above,
The shop obtain the data that a lot of consumers who bought sandwich also bought toothpaste a long with it.
From this data, the shop could make assumption that there is a correlation between the sandwhich and the tooth paste. (Maybe many of sandwhich buyers need the toothpaste to remove the sandwich's smell from their mouth). The shop could use this data and arrange the placement of the toothpaste so it's close to the sandwhich with the hope that it might increase its sales.