How coupon code curators like Honey and Slickdeals make millions

Promo code sites have become big business, with digital coupons surpassing paper for the first time in 2020. Far from a scam, online deal sites make millions on commission and big companies like PayPal and Goldman Sachs are buying them for billions. From Honey to Slickdeals, Rakuten Rewards to Brad's Deals, CNBC asked the major sites, and shoppers, what it takes to find deals that are real and why the business model works.