Why did P2P lending get a liquidity ranking of 6? It is quite possibly the most illiquid investment option you listed. You said you rank liquidity by “difficulty level of withdrawing your money without a massive penalty”, and for Lending Club notes, it’s not only difficult and extremely time consuming to sell all of your notes in their super illiquid market, but you would have to sell your notes at large losses to hope to get others interested in buying your notes. On top of that, it is impossible to withdraw your money any other way other than just waiting for interest/principal to pay off every month until maturity in 3 to 5 years. You can’t just one day tell Lending Club “I want to quit, please give me my money back.” One can even argue that it is less difficult to sell a home (in order to “withdraw” the money invested) than to withdraw all of their money from a P2P loan portfolio because it is very possible to sell a home before 3 to 5 years.
Mining contributed $63 billion (3% of GDP) and employed 20.14 million people (5% of the workforce) in 2016. India's mining industry was the fourth-largest producer of minerals in the world by volume, and eighth-largest producer by value in 2009. In 2013, it mined and processed 89 minerals, of which four were fuel, three were atomic energy minerals, and 80 non-fuel. The government-owned public sector accounted for 68% of mineral production by volume in 2011–12.
4. Save, build and run a bread-n-breakfast place. Look at airbnb Vacation Rentals, Homes, Apartments & Rooms for Rent - Airbnb for inspiration. My wife runs one (Firdaus, Naukuchiatal) , it is not an income as of now but if you are on it for enough time, it would be, when you grow old. It doesn't have to be a fancy and glamorous thing. It could be a 2 nice-n-clean room in a city where you live. If you have a big house, it could be a part of your house.
Affiliate and referral marketing involves driving sales for another business which then pays you a commission for each sale it acquires through your efforts. The Amazon Associates affiliate marketing program is one of the best options for people looking to earn money this way. You need set up a website with outbound links redirecting to products on Amazon (or another site that offers affiliate programs) and if a visitor from your site buys the product, then that business pays you a share of the amount spent.
The appeal of these passive income sources is that you can diversify across many small investments, rather than in a handful of large ones. When you invest directly in real estate, you have to commit a lot of capital to individual projects. When you invest in these crowdfunded investments, you can spread your money across many uncorrelated real estate ventures so individual investments don't cause significant issues.
Nobody gets early FI investing in bonds, CD’s, or even stocks unless they make a huge income or are extremely frugal or a combination of both. Paper assets just don’t provide enough returns. Business income can be great but it is typically not as semi-passive as I would like and there is a relatively high failure rate. That is if you can monetize an ideal to begin with. RE investing needs to be higher ranked IMO as a way that the “average guy” can become FI.
Retirees are paying a high price as the world stimulates its way out of the GFC (Great Recession). After a 30-year bull market to the lowest interest rates the world has ever seen, bonds have become highly priced and now don’t generate enough to meet income needs. Just 5 years ago the average income from $100,000 invested in a 10 year Australian Government Bond (10yrs) was $5,600 p.a. – now it’s less than half at $2,600 p.a.