Big fashion trends are dead, fashion designers have nothing like the power they once had and consumers won’t buy just anything retailers want to sell them.

To compete in a world like that, e-retailers need to be constantly listening to customers and getting to know what they want, Mariah Chase, CEO of plus-size fashion brand Eloquii Design Inc. (No. 816 in the Internet Retailer 2018 Top 1000), told the audience at the Internet Retailer Conference & Exhibition in Chicago on Thursday.

Mariah Chase, CEO, Eloquii

“The power axis has completely changed,” Chase says. In the past, fashion designers created “the dream,” retailers sold it and customers bought it, she says. The result has been a flat-footed industry that has not responded well enough to a changing marketplace in which customers are in charge of what, when and on what channel they buy.

Here is one way the lack of responsiveness has played out: According to Chase, 67% of American women wear sizes 14 and above—typically referred to as “plus size.” But only 20% of women’s apparel spending is in that category. She says women in that size category represent a $21 billion market that is under-served.

But taking advantage of that opportunity requires more than just making clothing in the right size, Chase says. It requires getting to know customers, meeting them on whatever channel they are on and creating a brand that stands for something.

One of the ways Eloquii gets the data it needs is something Chase refers to as “pre-tail.” The retailer previews items on its website and asks consumers to enter their e-mail addresses, along with their size and color preferences if they want to be notified when it becomes available. That, Chase says, gives Eloquii important data about the demand for those items and informs future merchandising decisions.

Chase says listening to customers and analyzing data have led to decisions it otherwise might not have made. For example, Chase says the decision to launch its swimwear line this year was based entirely on customer data. The plus-size retailer also is starting to use its data to implement dynamic pricing, which Chase says has led to some incremental improvements of margins for the items priced that way.

Opening stores—the retailer now has four and is opening a fifth in Houston this month—was another data-driven decision, Chase says. What Eloquii has found is that omnichannel customers are its most valuable ones. The lifetime value of a customer that shops across channels is three times that of web-only customers, she says.

Chase also says it is important for brands to stand for something customers can rally behind and build a community around because research shows that businesses with a purpose are more profitable than those that don’t. At Eloquii, that purpose is stated on the “About Us” page of its website: “We love fashion. We believe in its transformative power.”