Plus-size women’s clothing is a $20 billion retail market and poised to cross $50 billion by 2024, according to Acena Retail Group. Online retailers—both new and old—took note of that in 2017 in an effort to grab a piece of the market.

Let’s start with the new. Eloquii Design Inc. and Dia&Co, featured retailers in Internet Retailer’s latest Hot 100 list, each launched in 2014 as web-only retailers that exclusively sell plus-sized women’s apparel. For Dia&Co founder Nadia Boujarwah, she founded the site to offer a solution to a problem she’s faced when shopping for clothes.

“I’ve always loved fashion, but struggled to find clothes that fit my body and worked with my personal style,” she writes in a note on Dia.com. “I’ve been everything from a size 12 to a size 22 and I couldn’t help but notice, no matter my size, that there was nothing for me.”

Dia&Co runs a subscription-based model, in which a shopper fills out a questionnaire on Dia.com, and a stylist sends her selections she can try on at home. The shopper keeps what she likes and sends the rest back.

Eloquii, No. 546 in the Internet Retailer 2017 Top 1000 rankings, is a plus-size apparel manufacturer and online retailer. The company has raised $21 million, with the most recent round of $15 million in funding in 2016. At the time, Eloquii CEO Mariah Chase said company sales increased by 165% in 2015, declining to provide a sales figure. Internet Retailer estimates the company’s revenue crossed $30 million in 2017.

The retailer is using video to forge relationships with shoppers.

“Videos enable us to explain to prospective customers who we are,” says Kelly Goldston, vice president of marketing. “Shoppers want to like the people they’re buying from.” The retailer features one of its customers each month, highlighting her sense of style. Earlier this year, it launched a video series in conjunction with publicist and social media influencer Katie Sturino called Closet Confidential, wherein Sturino helps shoppers upgrade their wardrobes.

On the other hand, veteran plus-size apparel retail chain Ashley Stewart is focusing on omnichannel initiatives to drive growth. The retailer is investing in online and mobile marketing designed to connect online shoppers with its 89 stores.

For example, Ashley’s loyalty program, Diva Dollars, gives shoppers credits they can use in its stores and online. And the retailer’s website identifies customers who are within 10 miles of a store and shows them a pop-up window promoting events coming up at the local Ashley Stewart store.

A success story of the past year has been sending text messages to customers about four-hour flash sales at stores. While the retailer also tried texting to promote sales on its web and mobile sites, Julie Daly, vice president of digital commerce, says customers respond in bigger numbers to messages that promote sales at its stores. Lots of customers appreciate those text alerts: 418,000 have opted in to receive them, Daly says.

Additionally, online-only retailers such as Adore Me (No. 322), Nike Inc. (No. 37) and Stitch Fix (No. 134) launched plus-sized apparel lines for each of their businesses in 2017.

To read more about these companies and other innovative online retailers, download the free issue of Internet Retailer’s 2018 Hot 100.