In the case of viral marketing, "viral" refers to something that spreads quickly and widely across its audience. Viral marketing is a deliberate enterprise, though the distribution of a message happens organically. As such, social media provides the perfect ecosystem for viral marketing, though it has its roots in traditional word-of-mouth marketing. While the practice was much more widely used in the early to mid-2000s, as new internet businesses were being created in extreme numbers, it is still common among internet-based business-to-consumer (B-to-C) companies. The widespread adoption of social networks, including YouTube, Twitter, Instagram, Snapchat and Facebook, has enabled modern viral marketing efforts and increased their efficacy. 
Among the many passive-income opportunities that exist, interest is a very popular one, along with dividends. Unfortunately, we've been living in an environment of ultra-low interest rates for many years now, so even a savings account with $100,000 in it might only grow by $1,000 or $2,000 per year. Interest rates seem to be rising, though, so take heart -- and know that in many past years, bank accounts and CDs and bonds have paid rates of 5%, 8%, and even 10% or more.
I think also a very good way to earn a nice passive income is investing in Cryptocurrency, especially in Masternode Cryptocurrencies, which provide a passive income in coins, also those carefully picked coins grow in value, so it’s a double gain! And a great coin to invest in at the moment is GINCOIN, which is the fuel for a really succesful project. Find more at GINCOIN Website: 😉
Thanks for asking. gives a good summary of the definition I use. But in brief, it’s income that isn’t proportional to the time you physically put into acquiring it. It doesn’t mean it’s not without work or effort. It’s just that most of the work is done up front and it continues to pay off long after that initial effort. Real estate fits into that box. There’s definitely a spectrum but compared to what we do as doctors, where our compensation is directly linked to our time, most of these things are quite passive.

Exploits common motivations and behaviors. Clever viral marketing plans take advantage of common human motivations. What proliferated “Netscape Now” buttons in the early days of the web? The desire to be cool. Greed drives people. So does the hunger to be popular, loved, and understood. The resulting urge to communicate produces millions of websites and billions of email messages. Design a marketing strategy that builds on common motivations and behaviors for its transmission, and you have a winner.
In mid 2016, an Indian tea company (TE-A-ME) has delivered 6,000 tea bags[79] to Donald Trump and launched a video on YouTube.[80] and Facebook[81] The video campaign received various awards including most creative PR stunt[82] in Southeast Asia after receiving 52000+ video shares, 3.1M video view in first 72-hour and hundreds of publication mentions (including Mashable, Quartz,[83] Indian Express,[84] Buzzfeed[85]) across 80+ countries.
We pitched to an angel investor group. They were very excited about the idea but wanted to know who amongst us (doctor, accountant, salesman) was doing the coding. When they heard we were outsourcing it, the wind went out of their sails immediately. They did want to meet with us again once we brought a coder on board but that person proved elusive to find. Coders in our area are looking for the steady paycheck, not willing to gamble on a startup.
Diversify safely but DIVERSITY. You do not need to get the best and highest return all the time. If so, you are not earning passive income you are earning active income which is taxed differently (see IRS.GOV passive -vs- active income definitions). As an investor you do not need to be chasing ‘the almighty dollar’. This is a losing proposition. Make the dollar come to you.
2) Find Out What You Are Good At. Everybody is good at something, be it investing, playing an instrument, playing a sport, communications, writing, art, dance and so forth. You should also list several things that interest you most. If you can combine your interest plus expertise, you should be able to monetize your skills. A tennis player can teach tennis for $65 an hour. A writer can pen her first novel. A finance buff can invest in stocks. A singer can record his first song. The more interests and skills you have, the higher chance you can create something that can provide passive income down the road.
This can be a little easier said than done, but if you have a large social media following, you can definitely earn money promoting a product or advertising for a company. You can even combine this with different marketing campaigns if you are an influencer and have your own blog (advertisement + affiliate income). This is how many bloggers make money! Again, it is not 100% passive but once set up correctly and then scaled, can be surprisingly lucrative.
You can do anything – mow lawns, walk dogs, shovel snow, babysit, code online, tutor, make deliveries, drive people, flip on eBay, sell a product on Amazon, participate in focus groups, blog, or an infinite number of things. But not all side hustles are created equal since some can make you a lot more money than others. Fundrise. You can invest in real estate for only $500.
After these tenants move out, I'm thinking of just keeping the rental empty with furniture. It sounds stupid to give up $4,200 a month, but I really hate dealing with the homeowner association, move-in/move-out rules, and maintenance issues. Given that the condo doesn't have a mortgage and I have to pay taxes on some of the rental income, I'm not giving up that much. The condo can be a place for my sister, parents, or in-laws to crash when they want to stay in SF for longer than a week or two.
Peer-to-peer lending ($1,440 a year): I've lost interest in P2P lending since returns started coming down. You would think that returns would start going up with a rise in interest rates, but I'm not really seeing this yet. Prosper missed its window for an initial public offering in 2015-16, and LendingClub is just chugging along. I hate it when people default on their debt obligations, which is why I haven't invested large sums of money in P2P. That said, I'm still earning a respectable 7% a year in P2P, which is much better than the stock market is doing so far in 2018!

Some things aren’t funny: A 2013 UK ad for Hyundai used a failed suicide as a punchline (oh, haha, this guy wants to use his car’s emissions to kill himself, but the car is too efficient). A negative reaction ensued, including an open letter from a blogger who posted the suicide note of her father, who killed himself in the same manner attempted in the ad. (6)
Whereas Kaplan, Haenlein and others reduce the role of marketers to crafting the initial viral message and seeding it, futurist and sales and marketing analyst Marc Feldman, who conducted IMT Strategies' viral marketing study in 2001,[citation needed] carves a different role for marketers which pushes the 'art' of viral marketing much closer to 'science'.[23]