<p>Become a Gold Star Member and get a $20 Digital Costco Shop Card—here’s how.</p> <p>The post <a href="https://www.popsci.com/sponsored-content/costco-gold-star-member-plus-digital-shop-card-sponsored-deal/">How to join Costco for less than your friends</a> appeared first on <a href="https://www.popsci.com">Popular Science</a>.</p>