A money-saving expert says that buying gift cards is one of the best uses of your Costco membership - here's why

Flickr/Gary Stevens

Costco's gift cards.

• Costco offers discounts on gift cards bought in bulk.
• Examples include a package of four $25 movietickets.com gift cards you can get for $74.99, a $100 Cirque du Soleil gift card for $79.99, and a 12-month Spotify Premium membership for $98.99, which usually costs $119.88 plus tax, as was recently reported by Reader's Digest.
• There are other lesser-known perks to a Costco membership, such as gym membership deals, cheap gas, and discounts on vacations.

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

According to consumer-savings expert Andrea Woroch, its gift cards are one of them. These cards cover an array of activities from theater and movie tickets to restaurants, travel, and spa treatments, and by buying in bulk, you can save around 20%, Woroch said. That means that the total value of the cards that you have will actually be more than what you paid for them.

For example, there's a package of four $25 movietickets.com gift cards available for $74.99, a $100 Cirque du Soleil gift card for $79.99, and a 12-month Spotify Premium membership for $98.99, which usually costs $119.88 plus tax, as Reader's Digest recently reported.

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. Gas is a recurring purchase, and 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. This is a high-margin business because of the few administrative costs associated with it.

"It's not the value of that plane ticket and hotel - it's the broker commission," Galanti said in a recent earnings call.

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."