The surprisingly lucrative and competitive world of online mattress sales

Online mattress retailers Casper and Tuft & Needle exploded in popularity a few years ago. With more than 100 online retailers, the “bed-in-a-box” business is now a billion-dollar industry. It turns out that some of the biggest companies are in bed -- so to speak -- with the very people reviewing their products. Those reviewers are potentially raking in millions from those sales.