Some cards keep the same cash-back benefits year-round. American Express' Blue Cash Everyday card offers 3 percent back at the supermarket and 2 percent back when you get gas or shop at select department stores.
Often, the biggest benefits can be gained using credit-card companies' shopping portals on their websites. Mastercard's MarketPlace functions almost like Groupon or LivingSocial. When users log in, they're instructed to type in their zip code, which will pull up the deals closest to them, like $30 for a car-maintenance package that includes three oil changes and two tire rotations, or $49 for $2,000 worth of Invisalign invisible braces and teeth whitening.
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