<p>Discover savings on more than groceries and fuel.</p> <p>The post <a href="https://www.popsci.com/sponsored-content/costco-gold-star-membership-bonus-digital-shop-card-sponsored-deal/">Nervous about egg and gas prices? Join Costco and get a $20 reward</a> appeared first on <a href="https://www.popsci.com">Popular Science</a>.</p>