• Costco
  • gym-membership deals
  • gas
  • vacations

It might seem as if a Costco membership would be most useful to a family with lots of mouths to feed who wants to buy groceries in bulk, but there are several other savvy ways you can get the most of a membership.

According to Andrea Woroch, an expert on consumer savings, Costco's gift cards are one of them. These cards cover an array of things, from theater and movie tickets to restaurants, travel, and spa treatments. And by buying in bulk, you can save about 20%, Woroch previously told Business Insider, meaning the total value of the cards would actually be more than what you paid for them.

Examples cited in a Reader's Digest report include a package of four $25 MovieTickets.com gift cards for $74.99, a $100 Cirque du Soleil gift card for $79.99, and a 12-month Spotify Premium membership, which usually costs about $120 plus tax, for $98.99.

This isn't the only lesser-known perk of a Costco membership. Members can also get gym-membership deals, cheap gas, and discounts on vacations.

According to CEO Richard Galanti, Costco's so-called ancillary businesses, such as travel and gas, are fast becoming its biggest assets.

In the company's most recent earnings call in October, Galanti reiterated the importance of its gas stations in driving foot traffic — because gas is a recurring purchase, it's a way to attract members and keep them loyal.

Costco's travel business is an easy way to drive profits for the company, Galanti said in an earnings call in March, adding that it's a high-margin business because of the few administrative costs associated with it.

It's not "the value of that plane ticket and hotel," he said, but "the broker commission."

And it's designed to be a good value for the customer.

"Following the same philosophy as in the warehouses, we offer a limited number of products in an effort to focus on partners who consistently produce high-quality, exceptional value and superb service," Nikki Chellew, a Costco representative, told Business Insider last year. "Costco Travel adds to the overall value of the membership with savings that can exceed the cost of an annual membership."