Do you have $1 million to invest?
Make up some product - it can be completely imaginary - then hire Lebron James or Oprah or Dwayne Johnson to promote it for you on the internet and TV. People will give you tons of money for this imaginary product and, because humans don't like to be the only one doing something, they'll pressure their friends and family into buying it, too. You'll be invited to go on talk shows for FREE to promote your imaginary product, and at that point your advertising takes on a life of its own and you don't have to pay a dime for marketing.
Before long you'll be a billionaire, and as soon as you hit that mark get out.
That's the #1 reason why scammers go broke: they get greedy and don't fold when they should.