Participate in royalty-based venture financing. In traditional venture financing, an investor buys a stake in a company to provide growth capital to its founders. This investor is then entitled to a percentage of the gains experienced when a company is bought or has an initial public offering. However, there is another kind of venture financing where an investor can invest start-up capital in exchange for regular royalty payments that are based on the company's revenue. This doesn't give the investor any ownership in the company, but does guarantee regular payouts (assuming the company survives).
I used to be wary of Ebates (now called Rakuten) because I thought the cashback didn’t amount to much, but now I love it.  I’m converted!  To earn money through, all you have to do is sign in and then look for your online retailer and shop through the portal.  Then you get cash back in a few days (it says on the website).

How much money do you need to make passive income?