Investing in rental properties: Another form of real estate investment, rental investments (i.e. becoming a landlord) could steer you down the passive income path of steady monthly rent checks that you can use to pay off a mortgage loan on the rental property. After the mortgage is paid off, those monthly checks go right into your bank account -- potentially for years to come. 
Whatever you do, there is someone who wants to know how to do it too. I think selling your knowledge is key in a world of growing entrepreneurs. We need to be able to do it all, and online education is growing and expanding every day with new students waiting to learn what you know… so teach them and earn money while doing it through an online course on a site like Udemy!
The members and brokers that Brad recruited, as well as the members and brokers that those people recruited, were considered Brad’s “downline.” At the time of the divorce, Brad’s downline consisted of thousands of members and brokers, earning Brad a residual income of about $27,000 per month. The trial court was tasked with determining just how to divide the residual income, generated by Brad’s downline, between the two parties.
Passive income can also relieve the stress of the traditional product sales scenario. As you earn an active income, you are getting your finances from once source only. In this case, what if that source itself disappears for whatever reason? What will you do? No one will have your back. Besides, putting your financial eggs all in one basket is simply not good business sense. To be successful, you need to have taken control of your own income. Build your own website and you can control your own destiny. You’ll get out exactly what you put in.

Once you start to see some success, don’t be led astray by the money. While Flynn does use affiliate marketing to make money, he only ever recommends products that he has personally used and likes. He is inundated by offers to earn $50 per sale through commission on products he has never even tried. “I’m like, ‘I don’t even know you, I don’t know what this product can do, and I don’t know if this product will help my audience.’ I only use products I’ve used before, because that trust you have with your audience is the most important thing in the world.” He says if you do recommend a product for the incredible commission but your audience has a bad experience with it, your credibility will be shot.
4. eCourses: A step up from an eBook is an eCourse. These are a more thorough training that you can offer in a text format and typically include supplemental formats like video, worksheets, audio and more. This opportunity involves more work and likely an investment into a platform for delivery like Teachable, but you can also ask a lot more money. If you have been around the blogging world for any period of time you know it’s not unusual to see eCourses being sold for several hundred dollars if not more.
You can easily make it ‘customizable’ by creating a few different variations of the project. I’ve sold a customized personal investment plan on the site and deliver one of four different plans depending on the answers to questions sent by buyers. It involves almost no work after you’ve created the project so it’s an excellent source of residual profits.

If you know anything well, a place, how to fix something, how to make something, how to do something, you can write a guide for it. You can sell your guide as an e-book, offer it as a download for a fee on your site or reach out to bloggers with similar content and ask if they will offer it as a paid download on their website (for a price of course).

I wish I had more time to put into real estate. Given the run up since 2012, I may even be interested in selling my condo that I currently rent out. I need to get it appraised to really see what it’s worth, but I think conservatively it’s gone up ~50%, although rent is probably only up ~10% or so. I am bullish on rents going up in the future… mostly in line with inflation, or perhaps even slightly faster due to constricted credit and personal income growth which should provide a solid supply of renters. At this point, I just don’t want to manage the property. I’ll probably look into a property manager as my time is likely worth turning it into a nearly passive investment.
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.