Some good writing here! I am a realtor myself and frequently get in touch with clients that consider buying a realty estate a conservative of investing. I once heard of a transport company in Vienna, Austria, which focused their entire profit on buying eventually every house available in the downtown for about 80 years. That must be some of a passive income!

To model Viral Cycle Time’s effect on growth, I searched the web, high and low, looking for a pre-defined formula. To my great surprise, there was no formula that I could find that correctly calculated customer growth, and showed the impact of Viral Cycle Time. What was also surprising, was that I did find several blogs showing formulae for viral growth, but in every case, they appeared to make the same mistake, which was assuming that the entire customer base would continue sending out invitations for every cycle. So I collaborated with my partner, Stan Reiss, who turns out to be a whole lot smarter than I am, and he helped me develop the fomulae that are used in the more sophisticated model for viral growth below:
If retirement is a goal of yours (and who doesn’t want to retire someday?!?), it’s important to learn how to start investing. In fact, funding your retirement accounts should be at the top of your list. While these accounts won’t help your immediate situation, by stashing cash now, the residual income they create should help propel you through your golden years.
What I did: I first identified my favorite places in the world to live: San Francisco, Honolulu, Paris, Amsterdam, New York City, and Lake Tahoe. I then looked up the median rent and housing prices for each city. Then I factored in private education costs for two kids to be conservative given I may not have two kids and public schools are often good enough. After calculating all vital costs, I then did a self-assessment of how happy I was making $50,000, $100,000, $150,000, $200,000, $250,000, $350,000, $500,000, and $750,000. I decided working 20 hours a week making $200,000 a year is the best income balance for maximum happiness. 
The main risk coming from the company is for it to target the wrong influencer or segment. Once the content is online, the sender won't be able to control it anymore.[63] It is therefore vital to aim at a particular segment when releasing the message. This is what happened to the company BlendTech which released videos showing the blender could blend anything, and encouraged users to share videos. This mainly caught the attention of teenage boys who thought it funny to blend and destroy anything they could;[64] even though the videos went viral, they did not target potential buyers of the product. This is considered to be one of the major factors that affects the success of the online promotion. It is critical and inevitable for the organisations to target the right audience. Another risk with internet is that a company's video could end up going viral on the other side of the planet where their products are not even for sale.[65]
Basically, people looking to borrow money will make a listing on the site. Those borrowers are then placed into a category and given a “rating” based on their credit history and rate. You, as an investor, will contribute money to these loans and then be paid back at the predetermined rate of interest. Invest and see those monthly interest payments deposited into your account.
The ultimate goal of marketers interested in creating successful viral marketing programs is to create viral messages that appeal to individuals with high social networking potential (SNP) and that have a high probability of being presented and spread by these individuals and their competitors in their communications with others in a short period of time.[9]