Australian tech entrepreneur David Shein shares his recipe for success

Tech entrpreneur David Shein has has extraordinary business success in Australia. He migrated there from South Africa in 1986, where he founded and built up Comtec Communications into Australia's largest network integration company with 1400 staff. 14 years later, he sold the business for just over $1 billion - becoming the first Australian so-called "unicorn" - a privately owned start up valued by shareholders at over $1 billion. Since then he's become a start-up mentor and venture capitalist, helping other entrepreneurs get started. David Shein has just published a book - called The Dumbest Guy at the Table - all proceeds go to the mental health organisation Black Dog Institute. He talks with Kathryn about what he's learned through his career.