Image copyright Autumn de Wilde

The first thing Sophia Amoruso - chief executive of Nasty Gal, the fastest growing e-commerce site in the US - sold on the internet was something she had stolen.

A misfit who grew up hating school, Ms Amoruso left home at 17, intent on a life of anarchy and getting by for free in Olympia, Washington.

She says she received a rude wake-up call one day when she was caught shoplifting (but let off), which she had been doing in order to support her lifestyle.

"I learned the hard way that taking shortcuts and living for free is not really living free," she says.

Now 30, Ms Amoruso says that her early mistakes were crucial in helping her build Nasty Gal from a simple eBay store selling vintage items in 2006 to a $100m (£60m) business with more than 350 employees selling cool, quirky new and used clothing items to millions of women around the world.

Image copyright Sophia Amoruso / #GIRLBOSS Image caption Sophia Amoruso left home at 17 to become a "freegan" and an anarchist

"It was like throwing myself at the wall the way you throw spaghetti - to see if it sticks," she says.

Cinderella story

It goes without saying that Ms Amoruso is not your typical entrepreneur, and certainly not cut from the same cloth as the legions of technology bosses who flock to Silicon Valley in search of funding and riches.

After the shoplifting incident in 2003, Ms Amoruso moved to San Francisco, California.

Every other fashion brand out there - including those that I call competitors - are run by mostly old white men, and the customer knows it

A community college drop-out, she developed a hernia and so started work as a security guard checking IDs at an art school - a job she took for the health insurance it provided.

Bored, she decided to open an eBay store re-selling vintage clothing after reading a book called Starting an eBay Business for Dummies.

She named her eBay store Nasty Gal Vintage, after a song and album by the jazz singer Betty Davis, second wife of the legendary Miles Davis.

In her memoir, #GIRLBOSS, she says eBay was a crucial platform because she learned to respond to every customer comment, to really understand who was buying her finds and what they wanted.

That helped her beat other vintage sellers because she knew how to style the pieces she found - using young models who were paid a salary of burgers at a local restaurant - to appeal to her demographic.

Media playback is unsupported on your device Media caption Nasty Gal's Sophia Amoruso speaks to the BBC's Samira Hussain

'Old white men'

After a spat with rival sellers ended with her getting kicked off the auction platform, she struck out on her own, buying the domain name NastyGalVintage.com (NastyGal.com was initially owned by a porn firm) and communicating with her customers through social media sites such as MySpace and eventually Facebook and Twitter.

Nasty Gal by the numbers Image copyright NAStygal Founded in 2006 as an eBay store

Named fastest growing e-retailer by Inc magazine in 2012

$100m in revenue in 2013

1.2 million Instagram, and 300,000 Twitter followers

One million Facebook likes

"Using social media allowed me to have a conversation with our customers - I would say it was the number one reason we created awareness," she adds.

That put Ms Amoruso ahead of competitors who were just realising the power of social media to drive business.

"Every other fashion brand out there - including those that I call competitors - are run by mostly old white men, and the customer knows it," she says.

"This generation is super savvy - it doesn't matter who you hire to run your social media if the person behind the scenes pulling the strings is far from the customer."

Ms Amoruso says Nasty Gal amassed its 1.2 million Instagram followers and millions of Facebook likes by aggressively styling the firm's clothing in unique looks that "you can't find at the mall".

Image copyright PAul Trapani / #girlboss Image caption Ms Amoruso hired Paul Trapani and found models on MySpace to model her vintage finds in 2007

She pioneered the idea of styling outfits from head to toe and mixing old and new, expensive and cheap and made sure that Nasty Gal wasn't just a retail website, but a lifestyle that could appeal to a certain type of woman.

That has helped to build loyalty - most customers are women in their 20s who return again and again to the site, buying up 93% of Nasty Gal's inventory at full price. Half of the site's business comes from return customers - something almost unheard of in retail circles.

Sweat equity

Even after Nasty Gal started taking off - moving from a tiny office to a large space in Los Angeles - Ms Amoruso initially resisted taking outside investment, a rarity among tech firms, most of which aren't profitable in their early years.

"I had the luxury of a profitable business," she says.

Image copyright NASty gal Image caption Nasty Gal uses social media to communicate with customers and shape a lifestyle view

That allowed her to wait for the right investor - which took some time.

"When I decided to raise money, every guy was on to the fact that women like to shop as if it was the newest thing. They all had their theses and were ready to invest in any company that was making clothing for women, but there's no soul to that," she says.

Although she eventually found the right match in Danny Rimer, of Index Ventures, who pledged $9m in March 2012, she still retains a large amount of control, which has allowed her to hire smart people.

However, she does add: "It's only in the last six months that I can say my team has better ideas than I do - and how much of a relief that is."

Ms Amoruso has big plans for Nasty Gal - including opening physical retail stores later this year - and while she knows her rags-to-riches tale of a naive ingenue is appealing, she is careful to emphasise just how much hard work and what she calls "sweat equity" got her to where she is today.

As she counsels future "girlbosses" in her memoir: "Don't act like you've arrived when you're just receiving the invitation."