I have only dabbled in drop-shipping before when I had an eCommerce platform 6 years ago or so. I think it is something that you could do on the side, but you would want to do in depth research on the industry you want to get into before setting up shop. It may be a little less passive up front, but over time you could take your hands off the wheel.
Thanks for the great article…although I have to point out many of the items listed are not passive but active, such as selling bodily fluids, writing blogs or resumes, and collecting bottles and cans. To be truly passive, the income source must require no effort on your part (after initial setup). Real estate, dividends, P2P lending…these are truly passive income sources.
The model Quesnay created consisted of three economic agents: The "Proprietary" class consisted of only landowners. The "Productive" class consisted of all agricultural laborers. The "Sterile" class is made up of artisans and merchants. The flow of production and/or cash between the three classes started with the Proprietary class because they own the land and they buy from both of the other classes. Quesnay visualised the steps in the process in the Tableau économique.

With $200,000 a year in passive income, I would have enough income to provide for a family of up to four in San Francisco given we bought a modest home in 2014. Now that we have a son, I’m happy to say that $200,000 indeed does seem like enough, especially if we can win the public school lottery to avoid paying $20,000 – $50,000 a year in private school tuition.
If you’re curious about my own streams of income, I encourage you to check out my income report for an in-depth look. For now, though, I will tell you that I’m currently at twelve streams, beginning with my day job as an anesthesiologist, and ranging from crowdfunding to owning an apartment building, and to this very blog. Ultimately, having these multiple streams of income has proven to be invaluable to me–not only because of monetary value but because they allow me to live the life I want, and I feel I have a hedge against whatever the future might throw at me.
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).
The suggested analytical treatment of R&D expenditures is less definitive, but we can make a general statement that the ROE estimate for a mature company should reflect the long term productivity of the company's R&D expenditures: productive R&D expenditures increase ROE and residual income, and unproductive expenditures reduce ROE and residual income.
We have 1 rental at the moment and we are renovating the second one. Last year we generated over $14,000 net passive income (after mortgage payments and taxes) from one apartment, and all I had to do was go in to inspect the property 3 times to make sure the tenants weren’t destroying it! It turned out they kept it in perfect condition and they were lovely people! Call me lucky.

I am a very hard worker and am willing to do whatever it takes to make a substantial income but my questions for you is how could I do this at college? How could I generate enough income from multiple sources of flow that will keep me afloat for years to come? I am in desperate need for help. Thank you very much, I would be in great appreciation if I could get a response.
Blogging is still going to take work starting out. That path to $5,000 a month didn’t happen overnight but just like real estate development, it build up an asset that now creates constant cash flow whether I work or not. I get over 30,000 visitors a month from Google search rankings, rankings that will continue to send traffic even if I take a little time off.
The sky is the limit but some alternative income ideas are better than others.  Stanley and Danko in The Millionaire Next Door, are quick to point out that millionaires allocate their time, energy, and money efficiently, in ways conducive to building wealth.  That means that a millionaire is much more likely to spend Saturday mornings checking on his rental property rather than cruising garage sales looking to add to his garden gnome collection.  Robert Kiyosaki of Rich Dad Poor Dad fame likes to emphasize the benefits of a passive income.  The books aren’t exactly a prescription for wealth, but he makes two excellent points.  The first is that a stream of income that provides money when you’re sleeping is preferable to one that requires you to work.  The second is that passive income often enjoys much better tax treatment than the income from your professional work.  Here are some income streams that are fairly common among physicians:
Real Estate Crowdfunding ($9,600/year): Once I sold my SF rental, it was natural to reinvest some of the proceeds into real estate crowdfunding to keep sector exposure. I didn’t invest a lot in some of my favorite REITs because I felt a rising interest rate environment would be a stronger headwind for REITs. But if I could be more surgical with my real estate investments by identifying specific investments in stronger employment growth markets, I thought I could do better.
Not only that but in almost all other cases there is the illusion of influence, which is itself a psychological and emotional cost. If you invest in a business that your friend or family member is running, you can see how things can get messy. You have thoughts on how things should be done, they have competing thoughts, if things aren't going well… we know how this story goes.

Ask yourself how many hours a week do you spend sitting in silence, coming up with an idea and working on your idea? We’re so busy with our jobs that our childhood creativity sadly vanishes at some point in our lives. There are food bloggers who clear over $15,000 a month. There are lifestyle bloggers who make over $10,000 a month while living in Thailand. And there are even personal finance bloggers who’ve sold their sites for multi-millions.
Maybe such a business is owning a McDonald’s franchise or something. If one has the capital (Feasibility Score 2), then the returns might be good (Return Score 6). But the Risk Score is probably under a 5, b/c how many times have we seen franchise chains come and go? Like, what happened to Quiznos and Jamba Juice? A McDonald’s franchise was $500,000… probably much more now?

Ebooks, which can be published through sites like Amazon Kindle Direct Publishing, are an increasingly popular option. Because these books are self-published, the process is quicker, allowing you to build residual income faster than the traditional publishing route. Whether it’s a romance novel or a how-to book on fly fishing, you can create a book and have it available for purchase in a matter of weeks.

Here's another example. If a person owns apartments that are rented out at a profit, they earn money each month without working a specific number of hours. If the owner earns $100/month net income from each apartment, the determining factor is how many apartments they own, not how many hours they work. Therefore, they may own 1 apartment and make $100 net income each month, or they could own 500 apartments and make $50,000 ($100 per apartment) each month.