Another way to generate passive income is to invest and be a silent partner in a business. This is very risky, but with risk comes the potential for high returns. For example, several years ago both Lyft and Uber were looking for private investors to invest in their companies. Today, they are worth billions - but you as an investor would only reap that benefit if they go public via an IPO, or get acquired. So, it's risky.
You need to decide which machines you want to run, get the necessary licenses to operate them (you're selling items so you need to get sales licenses and whatnot from your state), buy the machines and a truck for the items in the machines, find a supplier of the products, and then finally you can secure locations. Finally, you need to service them periodically or hire someone to service them.

Ebooks are one of my favorite sources of passive income. Now, you can do this the simple way and just publish it on Amazon's KDP. Or, you can go all out and build yourself a book funnel. Book funnels are powerful, but they won't be fully passive. For example, if you do a free-plus-shipping offer for your ebook (converting it into a physical book), you'll need to create some one-time offers (i.e. extra training) and up-sells (i.e. an audiobook). But, a book funnel can be very powerful.

It shouldn’t come as a surprise, but people who regularly monitor their finances end up wealthier than those who don’t. When you were a kid, keeping track of all of your money in a porcelain piggy bank was pretty easy. As we get older, though, our money becomes spread out across things like car payments, mortgages, retirement funds, taxes, and other investments and debts. All of these things make keeping track of our money a lot more complicated.
Managerial accounting defines residual income in a corporate setting as the amount of leftover operating profit after all costs of capital used to generate the revenues have been paid. It is also considered the company's net operating income or the amount of profit that exceed its required rate of return. Residual income is normally used to assess the performance of a capital investment, team, department or business unit.