Answer:
since there was a rebate, most of the consumers were influenced by price and not by the quality or the healthiness of the cereal product.
so during the rebate period, the consumers bought more since they were sensitive to price, when the rebate ended suddenly, the demand and purchases dropped since people were no longer interested in the product and possibly went on to purchase substitutes.
in a more technical way, we can say that "Extrinsic rewards decreased the intrinsic value customers placed on the cereal"
Explanation: