Retailers do not know the real needs of the customer.They know only the information needs of its clients in the past times in the past.So he must forecast demand of customers.Then calculate the trading volumes of orders.
Retailers do not know the real needs of customers, they only know the information needs of its customers in time in the past, so he had to forecast customer demand and calculated Volume orders of the time.
Retailers do not know the real needs of customers.He knows only the information needs of customers in the shop the time in the past.So he had to predict the needs of customers.Then calculate the volume of the devil the order of that time.