Image copyright Getty Images Image caption Kylie Jenner founded a billion-dollar beauty company

Controversy is never far from the Kardashian family.

But it's not babies or boyfriends grabbing the headlines this time, but Kylie Jenner's new status as the world's youngest self-made billionaire.

Jenner, who has earned a 10-figure fortune aged 21, gained global recognition in her family's reality TV show Keeping Up with the Kardashians.

Though Jenner has made her fortune with her best-selling beauty business, Kylie Cosmetics, some have questioned whether her money can really be 'self-made', since she comes from such a privileged background.

Jenner welcomed her billionaire status with a post on Instagram thanking Forbes for the recognition.

She's also defended the notion that she's "self-made", telling Paper Magazine last month that none of her money is inherited.

In that interview, Jenner said "the self-made thing is true".

She claims her parents, Kris and Caitlyn Jenner, cut her off at the age of 15 and told her to start making her own fortune.

Jenner, who stars in the reality show Keeping Up with the Kardashians, continued: "What I'm trying to say is I did have a platform, but none of my money is inherited."

Image copyright Getty Images Image caption Jenner's make-up business generated an estimated $360m (£274m) in sales last year

Forbes has also weighed in on the issue, saying: "To be clear, Forbes defines "self-made" as someone who built a company or established a fortune on her own, rather than inheriting some or all of it."

The magazine has devised a scale ranking how truly self-made a business person is.

On Forbes' scale, media mogul Oprah Winfrey, who was born poor, scored a 10. Jenner, who has benefitted from being born into a famous, wealthy family, scored seven.

Bybreen Samuels, author of the business book Non-Profit Booster - 10 Steps to Building a Successful Organisation, believes "describing Kylie Jenner as a 'self-made billionaire' is a misnomer" because "at no time has she faced true entrepreneurial challenges".

Image copyright Getty Images Image caption Jenner in 2009 (left) and 2019 (right). Her dramatic transformation from demure teenager to red carpet regular helped her build her beauty brand

Samuels adds Jenner's journey to becoming a billionaire is in stark contrast with that of Sara Blakely, who used all her $5,000 (£3800) savings to launch the slimming knickers Spanx.

Forbes named Blakely the youngest self-made female billionaire in 2012, at the age of 41.

Samuels tells BBC News of Jenner: "She gained leverage by using her family name, fame and wealth. Consequently, she had direct access to the whole range of privileges, connections and resources that flow from these factors.

"Her ascendancy into global wealth and brand recognition was already guaranteed before she even started."

Predictably, given Jenner's background, opinions on social media about her 'self-made' status are split.

Skip Twitter post by @David_Leavitt Kylie Jenner is proof that all you really need to succeed in life is inherit a few hundred million dollars and already have preexisting international fame from your parents and siblings, and then it’s possible to make something of yourself. Clearly an inspiration to us all. — David Leavitt (@David_Leavitt) March 5, 2019 Report

How did Jenner make her fortune?

Image copyright Getty Images Image caption Jenner (centre right) became famous as a reality star, along with her mother and manager Kris Jenner (left) and her sisters, model Kendall Jenner (centre left) and Kim Kardashian-West (right)

Jenner was 10 years old when she made her debut on her family's reality TV series.

A decade on, she's the famous family's highest earner.

Freelance beauty journalist Jessica Morgan says Jenner's achievement shouldn't be underestimated.

"If Jenner hadn't come from a famous family, perhaps she wouldn't have been named the world's youngest billionaire so quickly," she tells BBC News.

"But that's not to say she wouldn't have achieved such an accolade in her lifetime."

Five facts about Kylie Jenner's business

Jenner started Kylie Cosmetics in 2015. Her empire consists of seven full-time and five part-time employees. Jenner trademarked the phrase "Kylie Lip Kits ... for the perfect pout" two years before setting up her company. She founded the brand with $250,000 (£190,200) she made through modelling and TV work. Her mother, Kris, looks after finance and PR in exchange for a 10% management fee.

Morgan continues: "On average, it takes a millionaire 14 years to reach billionaire status while the average age to hit this status is 37.

"It took Microsoft's Bill Gates five years to reach billionaire status, while Amazon's Jeff Bezos was crowned a billionaire after two years.

"I'm really happy for Kylie and I'm excited to see what else she has in store for us."

Image copyright Getty Images Image caption Jenner's savvy use of social media helped her make her fortune

With more than 175 million followers across Facebook, Instagram, Snapchat and Twitter, social media has been the key to Jenner's success.

So influential is she, that she wiped $1.3bn (£1bn) off Snap's stock market value after tweeting that she no longer used its Snapchat messaging app.

In May 2018, People reported that Jenner is the most valuable celebrity on Instagram, with each of her sponsored posts valued at around $1m (£750,000) in traditional advertising spending.

Morgan says beauty brands that use social media effectively can achieve huge success: "Emily Weiss built her beauty empire off the back of her blog, Into The Gloss, which garnered a huge following and subsequently led to Weiss launching Glossier.

"Jenner and Weiss both have one thing in common: they built their businesses using social media as a free marketing tool and it has worked. We can't argue with that."

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