Forbes recently released its list of America’s Richest Self-Made Women. Of course, it included powerhouses like Oprah and Sheryl Sandburg. But four women on this year’s list are beauty entrepreneurs. These beauty moguls are collectively worth nearly two billion dollars. Over the next three weeks, I’ll be profiling these amazing women and their companies. First up, Dr. Kathy Fields and Dr. Katie Rodan of Proactiv and Rodan + Fields, who are worth $650 million EACH.

Dr. Kathy Fields and Dr. Katie Rodan of Proactiv and Rodan + Fields

If you or anyone you know has suffered from severe acne in the last two decades, Proactiv has most likely been the answer. The company has earned an estimated one billion dollars in sales from 2015 alone, so it’s no wonder the powerhouses behind this brand are on this Forbes list.

Dr. Kathy Fields and Dr. Katie Rodan met at Stanford during their dermatology residency. They stayed close as they started practicing in a nearly all-male field in California. At the time, only spot treatments were available as acne treatments. But the dynamic dermatology-trained duo knew there was a better way, which led them to create the first full system acne treatment, Proactiv.

In the early stages of their product launch, the doctors first approached Neutrogena, who turned them down because their product required too much customer education and was priced out of the drugstore market.  Neutrogena advised Fields and Rodan to pursue infomercials, however, the pair wasn’t too keen on the idea. Infomercials were seen as lowbrow and cheesy. After being turned down by Neutrogena, the pair licensed the Proactiv to Guthy-Renker in 1995. Who in turn, ran (highbrow and celebrity endorsed) infomercials about Proactiv. Today, Proactiv is said to be worth two billion dollars.

A few years after Proactiv’s success, the pair created the aptly named Rodan + Fields skin care line. Rodan + Fields is the upscale sister to Proactive, targeted to women with anti-aging concerns. In 2002, Estee Lauder bought the company and placed the line in stores. However, they didn’t work out so well. In 2007, Katie and Kathy bought back their namesake company and changed strategy. Rodan + Fields would now operate as a multi-level marketing business. Think Avon and Mary Kay. Rodan + Fields would be sold by independent consultants who would recruit other consultants. And the higher you get, the more money you make. According to Forbes, there were 150,000 consultants last year.

A unique part of this business is its digital marketing and selling strategy. Instead of selling door to door or at traditional makeup and skincare parties, Rodan + Fields consultants use social media to sell their products. They’ve flocked to Instagram, Facebook live parties, and Periscope sessions to reach customers online. The consultants don’t buy and stock products themselves. All transactions are made on the consultant’s personal website.

The skin is the limit for this duo, who are looking to grow their company internationally. With that, I’m sure their spot on the Forbes’ America’s Richest Self-Made Women is secured for a long time to come.

Next week, we’ll meet Toni Ko of NYX Cosmetics.