Is it possible to have more than one income source?

According to author and entrepreneur Robert Kiyosaki's Book Cashflow Quadrant,

You can be make money 4 ways.

• You can get paid by trading time for money with JOB (Journey of the Broke)
• Becoming self-employed (Every day you start at Zero or worse)
• Be an investor or trade money for more money (Need it to invest with it)
• Build a business that creates leverage (Become come the next Walmart or Amazon)

Often times it take a great idea and lots of money to create a big company and the failure rate is high

What if you could get the "Big Company" to work for you and create a leveraged supplemental income steam?