Final answer:
The sales-promotion technique used by the phone manufacturer is referred to as a rebate. Ben completed the necessary steps and received a $50 check, which is consistent with rebate promotions.
Step-by-step explanation:
The sales-promotion technique used by the cell phone manufacturer in this scenario is known as a rebate. Ben followed the instructions provided by the manufacturer, such as filling out a form, attaching a copy of the sales receipt, and mailing these along with the packaging that contained a special code. In return for these efforts, he received a $50 check after a period of wait time, which is characteristic of a rebate, where a portion of the purchase price is returned to the customer after the sale to induce purchase and foster customer loyalty.