10 Successful Online Businesses By: Juan Cervantes

Mark Zuckerberg More than 1 billion people use Facebook each day, on average, viewing videos more than 8 billion times daily. A shift to mobile advertising has driven up the social network's revenues. And a year after buying virtual reality startup Oculus, Facebook announced it would start shipping the Rift VR headset in early 2016. All this helped push founder Mark Zuckerberg's fortune up nearly $13 billion to date in 2015.  Net Worth of $46.2 Billion 31 Years Old

Dustin Moskovitz Dustin Moskovitz helped launch Facebook with then- roommate Mark Zuckerberg from their Harvard dorm. He dropped out of school after two years and joined Zuckerberg in Palo Alto to develop Facebook. He left the social network in 2008 to start Asana, a software firm, but has held on to most of his Facebook stock. Moskovitz is married to former Wall Street Journal reporter Cari Tuna. $9.5 Billion Net Worth 31 Years Old

Jan Koum He had a knack for computers and got a job working at Yahoo as a security and infrastructure engineer for nine years under Yahoo cofounder and fellow billionaire David Filo, before leaving in 2007. Two years later he started WhatsApp, now the world's biggest mobile messaging service, with 700 million users. Facebook bought it for $19 billion in cash and stock in 2014. Net Worth of $8.7 Billion

Garrett Camp Garrett Camp is the cofounder and chairman of Uber, the car-hire startup that has seen its valuation grow almost 15 fold in the past two years -- to more than $50 billion. Uber wasn't Camp's first time behind the wheel: He also founded StumbleUpon--a Web discovery tool that's part Reddit, part Tumblr--and sold it to eBay in 2007 for $75 million Net Worth of $6 Billion 37 Years Old

Travis Kalanick Travis Kalanick is the CEO of Uber Technologies, the hot ride-hailing service that has raised almost $7 billion, including debt financing, from investors, who have valued the private company at more than $50 billion. Uber is competing with taxi services across the U.S. and in 64 other countries around the world. The company has been tearing across the globe, pledging to pouring $1 billion each into China and India as it tries to unseat strong local players and encountering bans and regulatory obstacles in Europe. Net Worth of $6 Billion 39 Years Old

Elizabeth Holmes Holmes founded Theranos at age 19, after her uncle died of cancer, to make cheaper diagnostic tests that require only a few drops of blood from a finger prick. Investors valued her company at $9 billion in 2014--on a par with Quest Diagnostics, and her 50% stake at $4.5 billion.  Net Worth of $4.5 Billion 31 Years Old

Nathan Blecharczyk Nathan Blecharczyk is cofounder and chief technology officer of Airbnb, which lists more than a million homes, or rooms in people's houses or apartments, for rental stays. As of November 2015, more than 60 million guests had used the service since it launched in 2008, including 17 million in the summer of 2015 alone. The company is now valued at more than $25 billion, after raising $1.5 billion in funding in June. Net Worth of $3.3 Billion 32 Years Old

Evan Spiegel In late 2013 Spiegel turned down a $3 billion buyout offer from Facebook. Snapchat raised $538 million in new funding in May 2015, reportedly valuing the company at about $16 billion. Net Worth of $2.1 Billion 25 Years Old

Bobby Murphy Rebranded as Snapchat, the product, which lets users send friends photos or videos with captions and graphics that "disappear" in 10 seconds or less, first started to take off in late 2011. "We weren't cool," Murphy once told FORBES about his and Spiegel's experience in college. "So we tried to build things to be cool."  Net Worth $1.8 Billion 27 Years Old