The plus-size apparel market has come a long way since its humble beginnings rooted in Lane Bryant's maternity section. With the rise of e-commerce, digitally native brands in the space have begun to crop up in recent years to offer more — and more stylish — options.

Modcloth and Eloquii are two of those brands. Over the last year, both have been acquired by big-box giant Walmart, which is keying in on the $21 billion market opportunity. That's how much American shoppers spent on plus-size clothing in 2016, according to market research firm The NPD Group. The segment is growing at twice the rate of the overall apparel market, with anticipated growth of 4% annually to hit $24 billion by 2020.

Despite the fact that many brands don't offer above a size 12 unless through a special plus-size collection, the average American woman wears a size 16 or 18, according to a 2016 study published in the International Journal of Fashion Design, Technology, and Education.

"It doesn't make any sense to miss out on 70% of female consumers in the United States alone," Universal Standard Co-Founder and Creative Director Alexandra Waldman told Retail Dive on the podcast.

Waldman and her co-founder Polina Veksler (who is also the CEO) launched their three-year-old digitally native brand with two main hopes. The first, to create a digital-first lifestyle brand that offers the largest size selection of any apparel brand. In October, they took a major step toward that dream with the launch of apparel in every size between 00 and 40. They also opened their first brick-and-mortar store, a long-term pop-up in New York City's SoHo neighborhood.

The company's loftier goal is to challenge the way in which all retailers and brands think about sizing, so that it's easier for women of all sizes to shop together. Universal Standard has set out to do that in part by working with retailers like J. Crew, Nordstrom and most recently Gwyneth Paltrow's Goop lifestyle brand to help launch expanded sizing collections.

"I think there is a tendency to default back to the old ways, the way things have always been done and I think that the more progressive brands are already seeing the writing on the wall and already making plans. The less progressive ones are going to have to catch up," Waldman said, adding that she hopes Universal Standard will set an example for how brands can approach plus-sizes in a way that benefits everyone from the consumer to the manufacturer.

You'll hear all this and more in this episode, so sit back, relax and listen. You can stream the episode below or subscribe on iTunes or Stitcher.