In 2017, a new athleisure company kept their story transparent and their leggings the exact opposite.

No see-through material. No waste. No pills, and no child labor or employee exploitation in the factory.

Sustainably and ethically made, leggings from Girlfriend Collective hit mailboxes in 2017, and the best part?

They were free.

Now, the company is worth $8 million.

It all started with a guerilla marketing style, free-giveaway campaign where all people had to do was pay for the shipping, moved into word-of-mouth marketing that highlighted the great quality, and ultimately meets at the present with the company’s reputation resting on sustainable practices and inclusive advertising.

InStyle interviewed the co-founders, Ellie and Quang Dinh, and found that the couple had three of their own goals in mind: 1) athleisure that was both chic and minimalist 2) sustainable and eco-friendly every step of the way and 3) a product the audience can trust.

Ellie Dinh told InStyle, “It’s kind of scary to purchase a $100 pair of leggings from a brand you’ve never heard of. We wanted people to trust us, and by giving people the product, we knew they would trust us—that’s how much we believed in what we’re doing.”

During that campaign, zero dollars were spent on initial advertising.

All that money went to sending the leggings to anyone who shared Girlfriend’s Collective post on social media and paid the $20-30 shipping for the $60-80 product.

Girlfriend Collective, therefore, made the most out of modern-day word-of-mouth marketing (also known as WOM marketing) and gave people something to talk about.

Consumers didn’t even have to look too far as to what they should say on their social posts— it was and is all on the About Page.

Avocado Magazine reports, “Want to know more about their SA8000 certification (SA stands for Social Accountability and includes child labor laws)? Girlfriend Collective has included every bylaw SA8000 puts forth. The list is exhaustive, but it’s the kind of list…you wish you could see from every company you purchase from.”

Each pair of the luxury leggings is made of 25 plastic water bottles and put together through a fair-trade factory in Hanoi, Vietnam.

The whole process not only saves 3.11 gallons of water and prevents around 18 pounds of CO2 emissions, but also allows for the factory workers to receive fair wages, rights to unionize, and work in safe conditions.

Girlfriend Collective rapidly became known as a company that does well because they do good, published in Forbes’ 30 Under 30: Wellness Tycoons in 2017, while Big Commerce reported that the company saw over 10,000 orders on the first day they finally launched their site. The result: their whole website crashed within the first two days due to the amount of users shopping.

Business Insider didn’t take long to jump on the Girlfriend Collective bandwagon, reviewing the leggings and free giveaway campaign as a stellar catapult into athleisure industry success.

“In that sea of options in my closet, there are a very select few that I really love — the ones that I know the feel of by memory and actually remember which company makes them so I can tell my friends when they ask,” Mara Leighton, a Reviews writer for the site, wrote.

And that telling of friends about the product is what WOM marketing is all about: get a product that has a story and get consumers to fall in love with that story.

According to Neilson, 92% of consumers put more trust into what their friends and family buy than any other form of advertising or marketing, meaning that relying on Word-of-Mouth marketing is not only free, but also necessary.

By trusting their product and crafting the transparent story of sustainability and all-inclusive marketing, Girlfriend Collective was able to use what Social Media Today calls “social currency.”

The article quotes a research study done by strategy group, Fractle, saying that “Facebook users are more likely to share content that educates their network, and/or makes them look good and reinforces a certain image of themselves.”

Girlfriend Collective did just that for customers.

The brand was able to create a foundation of trust, reputation, and good will that propelled their story forward to allow the word-of-mouth tactic to be so successful.

After all, their whole brand relies on “never putting our bottom line before what’s best for the planet”, with the slogan, “We’re Girlfriend Collective, and we’re glad you’re here. Recycle. Re-Girlfriend.”

Forbes also highlighted the importance of word-of-mouth marketing, reporting that “for the last few years, marketers have been focused on ‘collecting’ instead of ‘connecting’” and that “having 100 really passionate fans that love your brand or product is exponentially more effective than having 10,000 “fans” who signed up just to win a free iPad from you.”

Girlfriend Collective has become a prime example of how to connect to consumers moral compass as well as their passion for using their consumer power.

And the brand’s success continues a steady upward climb, growing not only in social media followers, revenue, and sustainable credibility, but also has expanded their athleisure line into more sizes and colors.

When the campaign first launched, the free leggings were the initial basic black “Girlfriend” legging and that was all one could buy from the site until March 2018, when two new colorways became available.

Now, the site offers leggings in many different colors and a whole variety of styles, along with sizes ranging from XXS to an XXXL and the marketing images to show all kinds of body types.

No “body” is left out, and that only adds to their story that gets told from woman to woman.

The company was able to hit a trifecta: free leggings to sustainable practices to inclusivity in sizes and marketing.

Jordan Pietrafitta, a recent Advertising graduate from Pennsylvania State University, actually got to research this story— covering its many inclusive, sustainable facets— in her Schreyer Honors College thesis titled, “Creating Change in the Fashion Industry: An Advertising Campaign to Bring Together Diversity, Inclusivity and Sustainability.”

In her research, she found that Girlfriend Collective’s rapid ascent was all due to their ability to give consumers exactly what they asked for: sustainable choices and body representation.

“After extensive research into diversity, inclusivity, and sustainability practices of the fashion industry, Girlfriend Collective is one of the few brands that comes out on top for all categories,” Pietrafitta said. “It’s a brand that is inclusive of all body types, races, genders, ages, and abilities while emphasizing the immense need for a sustainable, zero-waste future by using recycled water bottles to make their products.”

This word-of-mouth story involving sustainability and inclusivity— something that clearly consumers have long been waiting for— became impossible not to tell, and is something other sustainable fashion companies should follow in example.