In general, nine out of 10 startups fail.
But the ones who make it all have one thing in common: a brilliant idea.
Like these self-made billionaires did with their companies.
Larry Page and Sergey Brin were PhD students at Stanford when they first came up with the idea of a search engine. But their idea was a little different than the other search engines in the market: it would examine the number and relevance of links between pages, not just the keywords on them.
Mark Zuckerberg was a Harvard undergrad when he came up with the idea of a 'hot or not' type of website called Facemash. From that site, Zuckerberg learned how technology could be used to connect people and launched a site called thefacebook.com.
Later, he changed the name to Facebook, and in less than a decade, turned it into a $250 billion company. Zuckerberg is now worth over $35 billion.
President, founder and CEO of Facebook Mark Zuckerberg speaks during a Reuters interview at the University of Bogota January 14, 2015.
Working as a Wall St. trader in the 1970s, Michael Bloomberg quickly realised financial companies were willing to pay big bucks for reliable business information. Bloomberg launched a business that provided important financial information quickly through dedicated computer terminals.
Bloomberg, with over $8 billion in annual revenue, is now one of the most powerful media and financial information companies in the world. Bloomberg's net worth is estimated to be roughly $37 billion.
Jeff Bezos was working at a Wall St. firm in the early 1990s when he decided to start his own company. He eventually settled on an idea to launch an online book store.
Now Amazon sells everything from books and furniture to gadgets and wine. It's worth about $200 billion with over $88 billion in annual sales. Bezos is estimated to have a net worth over $38 billion.
Growing up in Chicago's south side, Larry Ellison had a rough childhood, dropping out of college twice. But once he moved to California at age 22, in the mid 1960s, he came across an IBM report about a database programming language called SQL.
Inspired by the IBM paper, Ellison took SQL and created the Oracle database, which could run on non-IBM computers. After a few years, Oracle took off, becoming the most popular database ever sold. Now Oracle is worth $195 billion, and Ellison is one of the richest people in the world with a net worth estimated at around $65 billion.
Oracle executive chairman and CTO Larry Ellison
In 1975, cofounders Bill Gates and Paul Allen came across an ad for the Altair 8800, one of the earliest forms microcomputers. They built a programming language called BASIC, which became the foundational code for Altair 8800.
Soon, Microsoft built an operating system called DOS and licensed it to IBM. A few years later, Microsoft built Windows that had a more graphical interface than DOS. Since then, Microsoft has become one of the biggest tech companies ever, dominating the PC and software market. It's a $370 billion business spanning servers and data centres, as well as video games and mobile phones. Gates is the richest man in the world with a net worth approaching $80 billion.
Marc Benioff had a revolutionary idea when he founded Salesforce in 1998. He wanted to deliver software over the web, or the 'cloud,' making it faster and easier to install and update.
Salesforce started out as a service for salespeople, but now it has different software for marketing, customer service, and even data analytics. It's one of the fastest business software companies to ever reach $5 billion in sales, and Benioff is worth about $3.8 billion. He's also credited with pioneering the cloud market, which is now one of the hottest areas in tech.
Mark Cuban was an early internet entrepreneur in the 90s, and built a company called Broadcast.com based on the idea of providing customised satellite broadcasts over the web.
He later sold Broadcast.com to Yahoo for $5.7 billion. Broadcast.com no longer exists, but there's no question Cuban - now worth about $3 billion - is one of the most successful self-made tech entrepreneurs of all time. He's also the owner of the Dallas Mavericks and an active startup investor. His role on 'Shark Tank' has turned him into a popular TV personality as well.
Jack Ma was captivated by the internet after visiting the US in 1995. He soon launched two internet startups which both failed. As his third venture, Ma started an online marketplace where exporters could post product listings so customers could buy directly from them.
Jack Ma giving a speech to his employees in 1999 from his apartment