The link that I have posted in the previous comment is not easy to negotiate so I have copied the salient points and reproduced them here
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Rebate (marketing)
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For other uses, see rebate (disambiguation).

.A cashback rebate is an amount paid by way of reduction, return, or refund on what has already been paid or contributed. It is a type of sales promotion marketers use primarily as incentives or supplements to product sales. The mail-in rebate (MIR) is the most common.

A MIR entitles the buyer to mail in a coupon, a receipt and barcode in order to receive a check for a particular amount, depending on the particular product, time, and often place of purchase.

Rebates are offered by either the retailer or the manufacturer of the chosen product. Large stores often work in conjunction with manufacturers, usually requiring two or even three separate rebates for each item. Manufacturer rebates are sometimes valid only at a single store. Rebate forms and special receipts are sometimes printed by the cash register at time of purchase on a separate receipt or available online for download.

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Personal computer components and electronics seem to have a large portion of rebate sales. For example, an item might be advertised as "$39 after rebate" with the item costing $79 OTD (out-the-door) with a $40 rebate that the customer would need to redeem. The turnaround time is generally four to eight weeks, though some rebates note a period of eight to twelve weeks.


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