And while real estate is an excellent option, it does require a significant initial investment, so whether or not this passive income stream is right for you depends on your current financial situation. You might be better off starting with an investment strategy where you can build funds until you have a big enough sum to get involved in real estate.
There isn’t an exact formula to make your viral marketing campaign a success. In fact, going viral is one of the most difficult things for marketers. It isn’t possible to perfectly predict what can make or break a viral marketing campaign. However, the above tips should certainly be on your radar to improve engagement and increase your chances of becoming viral.

Love your articles. I think everyone is very different as far as how much passive income they need to meet their goals. I’ve read a lot of your articles and really enjoy your thoughts. I have a masters in finance and understand the math of keeping the debt but my emotions are such that I need to try to finish off paying off my last debt (mortgage) in the next two years. At 34 and only worth 525k I’m doing better than a lot of folks my age but it will be difficult for me to catch up in the passive income game without leverage. That is the main reason I recently created a website to try to bring passive income opportunities in my area to me.
To save time and effort, a person can group two or more of their passive activities into one larger activity, provided they form an "appropriate economic unit." When a taxpayer does this, instead of having to provide material participation in multiple activities, they only have to provide it for the activity as a whole. In addition, if a person includes multiple activities into one group and has to dispose of one of those activities, they’ve only done away with part of a larger activity as opposed to all of a smaller one. 
This “use” can be as simple as wanting to see a hated popstar get his image shredded. It can be finding out how to survive a zombie apocalypse. Besides use, today’s consumers want to feel like they’re part of your product. This can be as simple as rewarding them with your product for an action, or including them vicariously through visual content that incorporate people just like them.

However, this comes back to the old discussion of pain versus pleasure. We will always do more to avoid pain than we will to gain pleasure. When our backs are against the wall, we act. When they're not, we relax. The truth is that the pain-versus-pleasure paradigm only operates in the short term. We'll only avoid pain in the here and now. Often not in the long term.

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.
Since publishing this post, I created a SlideShare presentation that has a several additional ideas on viral marketing: The Science behind Viral Marketing. Also check out Andrew Chen’s blog, as he has written extensively on the subject of Viral Growth. For example, here is one great example: What’s your viral loop? Understanding the engine of adoption.

Among the first to write about viral marketing on the Internet was the media critic Doug Rushkoff.[16] The assumption is that if such an advertisement reaches a "susceptible" user, that user becomes "infected" (i.e., accepts the idea) and shares the idea with others "infecting them", in the viral analogy's terms. As long as each infected user shares the idea with more than one susceptible user on average (i.e., the basic reproductive rate is greater than one—the standard in epidemiology for qualifying something as an epidemic), the number of infected users grows according to an exponential curve. Of course, the marketing campaign may be successful even if the message spreads more slowly, if this user-to-user sharing is sustained by other forms of marketing communications, such as public relations or advertising.[citation needed]