Not all buyers will meet the criteria to receive the rebate. Companies often require the original UPC barcode, receipt, and additional information, which a buyer may forget to include when redeeming the rebate. Companies almost always add other caveats to the rebate as well, such as the redemption having to be postmarked by a certain date. Another tactic that might be used is to disguise the rebate mail to look like junk mail, so that the customer may overlook it. Rebate processing companies even pride themselves for "returning the least amount of money". It works in the company's favor if buyers do not act quickly to redeem. However, a University of Florida study notes that shorter redemption periods actually increase the redemption rate in the consumer's favor because it gives them less time for procrastination to set in.