Among the top reasons why startups fail is because the founders butt heads and are unable to get along.But when you go into business with a sibling, chances are you’ve probably had at least 20 years to figure out if you get along and if you work well together.
So starting a business with your bro or sis can be an advantage. Generally you don’t have to worry about trust issues and any equity disputes can usually be resolved within the family.
So it’s no wonder why a number of startups are founded by siblings.
Two years ago, these Irish brothers, then 17 and 19, impressed the Silicon Valley VC community when they got accepted into Paul Graham's YCombinator.
Soon after, they sold their software company, Auctomatic, to a Canadian media company for $5 million.
Now the brothers are working on a new business to business payment startup called Stripe, and it's being funded by cream of the crop Silicon Valley VCs, including PayPal founders Peter Theil and Elon Musk.
The Cook siblings have been the talk of the startup world lately.
Because, in 2005, as high schoolers in a new neighbourhood in New Jersey, Catherine and David Cook decided to create an online yearbook to more easily meet other students. They called it myYearbook.
Within a week, they had 400 users at their school, and nine months later, they had one million! Read their story.
Seeing the success of myYearbook, Catherine and David's older brother, Geoff, himself an entrepreneur, helped his little brother and sister find programmers and raise VC money. Nice to have an older brother with those connections.
This month, the three Cooks sold myYearBook to Quepasa, a social media technology company, for $100 million. And it's all staying in the family.
Ali and Hadi are both entrepreneurs in their own right.
Ali co-founded a company called LinkExchange, which was acquired by Microsoft in 1998 for $265 million.
So you might think that his twin brother, Hadi, would feel a little envious.
But no. That's because Hadi co-founded a separate company which he also sold to Microsoft - for about $800 million!
In 2002, they pooled their entrepreneurial genius to create iLike, a social music discovery service, which they sold to MySpace in 2009, reportedly for $20 million.
At 25, Zach Coelius moved to San Francisco from his native Minnesota as a Silicon Valley outsider.
But with a lot of persistence and a strong poker game, he won the favour of some influential VCs - and got some to invest in his media buying website, Triggit.
A partner at Bay Partners, who he played poker with, gave him $500,000 in 2007, and in 2010, Triggit raised $4.2 million from a number of investors, including Spark Capital and Foundry Group.
Zach's sister, Susan Coelius Keplinger, who Zach had worked with on other entrepreneurial ventures, joined the team as Chief Operational Officer.
While a sophomore at Harvard, James came up with the idea for Paperless Post, an upscale, advertising-free version of Evite.
Realistic-looking invitations slide elegantly out of virtual envelopes, and the business model is that the user pays for every invitation - using virtual stamps.
James pitched the idea to his sister, two years older, she liked it, and they launched the company together in 2009. As of January, they had raised $6.3 million and the company is headquartered in Manhattan, where they grew up.
Appstem Media, which designs mobile apps, was founded in 2010 by the Woolery brothers, two of them identical twins, Hart (CEO) and Gavan (CTO), and Eli, who is Creative Director.
Together, the brothers have what seems like entire lifetime of programming experience.
Among other programming positions, both twins were software engineers for a company that was acquired by AOL. And Eli studied mechanical engineering at Stanford and worked as a design engineer for a company that does underwater research.
Bertrand and Roy immigrated to the U.S. from Mexico as teenagers in 1986.
In the late 1990s, as the dot com era was booming, and e-commerce was growing rapidly, the brothers realised that there were a lot of people, many of them poor immigrants, who wanted to buy things online, but could not because they didn't have bank accounts or access to credit.
So in 1998, the Sosa brothers launched NetSpend, which sells reloadable debit cards at over 30,000 locations, including grocery stores, mostly throughout Texas and Mexico.
In 2007, Capital One purchased NetSpend for $700 million in cash.
Now, the Sosas run a venture capital firm called MPOWER Labs; its mission is to 'build companies whose products help the world's underserved.'
There is hardly a sentence in English about Ferry and Fabian online.
But in 2009, these German brothers founded DailyDeal, which is apparently one of Europe's leading daily discount sites and one of Germany's fastest growing startups.
In 2004, Blake and Jason, four years apart, founded Sling Media, maker of the Slingbox, which allows consumers to watch their home TV on any Internet-connected PC, Mac, tablet or smartphone.
In 2007, Sling Media was acquired by EchoStar for $380 million. Not bad, brothers.
The Musk brothers, originally from South Africa, have done a lot on their own.
Elon was a co-founder of PayPal, which eBay acquired for $1.5 billion.
So you might be thinking that Elon is a lot richer than his brother, Kimbal - which may be the case.
But Kimbal was one of PayPal's earliest investors, and he has also invested in Tesla Motors and Space X.
Kimbal is a restaurantuer. He is a graduate of the French Culinary Institute in New York, and in 2004, he opened The Kitchen, a community bistro in Boulder, Colorado.
Together, Elon and Kimbal founded Zip2 back in 1995. Zip2 was the first company to provide maps and door-to-door directions on the Internet.
In 1999, Compaq bought it for about $300 million.
Esteban and Eduardo Salazar have the newest company on this list - it's not even a month old.
Their company is Dittit, which enables people to acheive personal goals using automated financial penalties.
They are currently part of Startupbootcamp Madrid, a European startup accelerator program affiliated with Techstars.
They are so new that it's impossible to find a photo of them, but they've got a good idea.
Good luck, Salazars! Maybe you can make millions like the other brothers on this list.