Final answer:
CamScan is offering a rebate, which involves returning part of the purchase price after the buyer sends in a form and proof of purchase.
Step-by-step explanation:
In the scenario described, CamScan is offering a rebate as a type of sales promotion. A rebate is a return of part of the purchase price by the seller to the buyer, which typically requires the buyer to submit proof of purchase and a form to claim the cashback. This differentiates it from other types of sales promotions such as premiums, which are gifts that come with a purchase, bonuses, which are extra items added to an order, or coupons, which provide a discount at the time of purchase.