One of the oldest plus-size brands is fixing the only problem holding it back from a $17.5 billion gold mine

For decades, images of ultra-slim models have appeared in windows, on magazine covers, on billboards, and on television.

But thanks the prevalence of curvy supermodels like Denise Bidot and Ashley Graham, the curvy woman is becoming en vogue.

It's a welcome message in the US, where the average woman is a size 14 and 65% of women are considered plus-sized. 

Despite the shift, curvy women complain they are consistently ignored by fashion retailers, who fail to offer flattering designs.

Lane Bryant is hoping overcome its biggest problem - a reputation for being dowdy -to change that. 

Lane Bryant has long been the champion of the plus size woman.  After all, it is a plus-size retailer. Recently, it's become the curvy woman's most vocal advocate, as it has managed to hit nerve after nerve with its viral campaigns, proudly declaring that its shoppers can be #NoAngel - a not very subtle jab at Victoria's Secret.

There has been a myth that curvy women don't want to dress stylishly, but that's not true - in fact, she'll spend money on the clothes; nevermind the fact that according to industry research firm NPD Group, the sector is worth a vast $17.5 billion dollars.

But the company has had a problem for its history: the clothes have a reputation for being matronly and outdated. 

That's slowly changing. 

The company made two crucial hires in the past several years. In 2013, its CEO and President, Linda Heasley came on and the company tapped current CMO Brian Beitler in 2014. It's arguable that together, they've been helping Lane Bryant slowly change public perception of the company.

That slow burn started with the company's viral campaigns, the first of which was the  #I'mNoAngel - the campaign that appeared to take direct aim at Victoria's Secret's "Perfect Body Campaign." The company swears it didn't set out to attack Victoria's Secret.

That mantra - that curves should be seen - has echoed through the company's subsequent viral campaigns.

#I'mNoAngel was followed by this past fall's #PlusIsEqual. Lane Bryant's most recent campaign, #ThisBody, has gained attention for being banned from major television networks - though NBC told Business Insider that it required an edited version of the spot, something that it routinely asks brands to do.

"We were asked to edit out certain elements and we felt very strongly that this was a tasteful, beautiful celebration of who she is and we felt that the campaign need to be shown in its entirety and that was important to us. It was supposed to be a celebration," Heasley said. "It's supposed to be about challenging perceptions of what this woman is and what's acceptable to be shown in media that's consumed by many."

"We wanted to elevate the imagery that is associated with this client and I'm proud of the campaign and I'm proud of the entire spot," she said.

These campaigns are viral and provocative in nature, and that's intentional.

"We didn't have the budget that those brands [like H&M and Forever 21]  but had to create the impact," Beitler said. This is  imperative, because the retailer needs to consumers to "how the brand is evolving [and the] fresh change."

But getting people to realize Lane Bryant has changed - let alone open their eyes (to ultimately open up their wallets)- remains a challenge. The retailer has over 700 stores and 110 years of history. Though media savvy consumers might quickly share a photo, that might not win over the millions of over consumers that need to be persuaded.

Case in point: in a failed recent Twitter chat called #AskLaneBryant, consumers lashed out at Beitler for that reason: the marketing swears it's for the plus size woman, but the clothes say the opposite. Shouldn't a company that it's strictly for curvy bodies make clothes that flatter them, rather than resort to the frumpy frocks that prominently straight-size companies sell?

Both Beitler and Heasley were surprisingly quite optimistic about this blunder. It seems as though it served a reminder that plus size women want stylish apparel, and that just some nominally trendy clothes might not be enough.

"The chat - I heard that loud and clear. They want even more fashion from us.," Heasley said.

Beitler echoed that sentiment "I think what we learned from the Twitter chat is that the consumer continues to demand more," he said.

Beitler isn't blind to how many women have perceived Lane Bryant.

"Arguably, the brand several years ago had lost its way, and since Linda [joined] we've [recognized] the desire is there for even more and to do it faster and to do it better. And that's okay for brands to experience those requests," he said.

"All of us need to push ourselves to be better on that front, relative to fashion. She deserves [it]. I read every comment. I take it to heart, and we work to deliver what she wants," Heasley said.

"This customer is willing to pay to ensure the fashion she deserves and I think there's been a bias that they really won't [pay]," Heasley said.

So how does Lane Bryant specifically plan to do this? By promising to hone in on style. The company has a forthcoming collaboration with Christian Siriano - his first designs for plus sizes. The company has some secret collaborations up its sleeves, and has been utilizing curvy fashion icons like Denise Bidot and Ashley Graham in its campaign. It's even partnered with Glamour. Heasley wants the long-ignored sector to "get the unique product that she hasn't been able to get."

However, other companies have been savvy to the space in the market. Target has continued to expand its plus-size Ava & Viv line, even though an early review on Jezebel called it simply "meh." Forever 21 has a plus size sector. And though offerings are bleak compared to what's in the straight size markets, some designers do sell for plus sizes.

In the meantime, the company is zeroing in on its message, and fortunately, it's resonating to some extent. Comparable sales went up 2% in the past quarter.

Beitler believes that some of this success is attributable to the more body positive millennial generation. "I think the millennial mindset has been an impressive impact on ... inclusivity," he said. " I can't wait to see what Gen Z says [about it]." 

"I hope that we all become less judgmental. I think future generations will think its ludicrous that we differentiated and segregated this client... I see this with this young [generation coming up," Heasley said

After all, Lane Bryant's frequent campaign star Ashley Graham received a cover on Sports Illustrated, sending a resounding message to consumers that curvy women can be embraced by even the alpha male who traditionally reads the page. More telling was the prominently featured Lane Bryant ads in the magazine, as well.

Beitler also informed Business Insider that the company is not resorting the heavy promotions that have been cursing other retailers lately.

"What we know is we know price has always been and will always be important to consumers you always want to feel like you're getting good value for the money that you're spending ... it's just that value can be defined in a lot of ways," Beitler said.

That could be price or something that's more long lasting. But can a company's ethos equate to value - especially in an era in which it's hard enough to get consumers to spend on apparel as it is?

Lane Bryant appears to simply have the goal of making sure that these women feel represented - be it through clothes or marketing. 

Ultimately, Heasley says that "the core of our message is a movement and we're demanding humanity in an industry that's meant to exclude and we're saying, 'no. Let's be inclusive. Let's celebrate women.'"