Shopping for presents during the holiday season is stressful enough. (Did you forget anyone? What do you get that one person who has everything?) And once you’re finished, you’ll inevitably get loads of emails—because you’re now on every mailing list—with all of the sales you’re missing. It’s not that you think your friends and family aren’t worth the sticker price, but the sting of a sudden price drop defines “impotent rage.” Who doesn’t want to save a few dollars if they can?

That’s where Paribus comes in. Head over to the company’s site, create an account, and link your inbox to keep track of all of your online shopping. If a store lowers a price on a product you bought, Paribus does all the legwork in filing a price adjustment claim. (Who knew you could do that?) If you make money, they take a 25 percent cut, but you don’t even lift a finger. It’s so easy, the real question is: What are you waiting for?