I found this to be a fascinating and most helpful book. It was so motivating I'm already working on three new streams of income, and about to start a fourth. Forget net worth! Cash flow is much more important, particularly if you're retired. Only one slight criticism of the book. It's a bit dated, but those few parts make little difference to its overall value. If you're currently struggling with how you're going to survive after you retire, try Allen's approach. It will open your eyes.
The type of business you should start depends on your passion and existing skill set. If you love baking, for example, you could consider starting a home-based cake or brownie business. Love to sew? Spend your free time creating the perfect crafts, then turn around and sell them with your own Etsy store. Love dogs? Consider watching dogs out of your own home and marketing your services on a website like Rover.com.
Coaching – I’ve been coaching ever since I was in college and I love it. And since I coach a club team, the time commitment averages only about 10 hours a week. The money isn’t great if you depend on it for living but it’s the perfect secondary source of income since it’s very easy for me to get hired as a coach(and it’s tax free through business deductions).

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.
John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Selena Maranjian owns shares of Amazon, Costco Wholesale, National Grid, Realty Income, and Verizon Communications. The Motley Fool owns shares of and recommends Amazon, eBay, National Grid, and Verizon Communications. The Motley Fool recommends Costco Wholesale, Lowe's, The TJX Companies, and Welltower. The Motley Fool has a disclosure policy.
These are just a few ideas to get you thinking about what you can do to create a multi-streamed income. Your project might turn into a full-time job in itself or it could just be a back-up plan that gives you peace of mind while you continue to work a day job. Finding extra work that you really enjoy can be a great way to share your skills, meet new people, and take your personal finances to the next level. 
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.
Rentals, just like stocks, throw off cash. With rentals we call that cash “rent”, and with stocks we call it dividends. A significant difference however is that the S&P 500 has appreciated at ~6% per year (above inflation) for the last 100 years…..Real Estate has had almost 0 growth above inflation. So are rents higher than dividends? Maybe, maybe not. But unless you got one heck of a deal, the delta in rent over dividends will have a very tough time making up for the 6% per year difference in appreciation.
However, you should pick a niche and blog about that. If you're launching a money related blog, maybe it'll be about how to make money in real estate or simply how to make money online. Pick the niche and stick to it. If it's a diet and fitness related blog, maybe the niche is the Ketogenic diet, the Atkins diet or some other form of diet or fitness.

This world is a dangerous place to live, not because of the good people that often act in irrational and/or criminally wrongdoing ways within the confines of their individual minds, core or enterprise groups, but because of the good people that don’t do anything about it (like reveal the truth through education like Financial Samauri is doing!). Albert Einstein and Art Kleiner’s “Who Really Matters.”
Maybe you’re obsessed with homemade jewelry and want to sell your wares on Etsy. Or, perhaps you’re well-versed on the Amazon reselling game and want to earn extra cash finding unicorns (rare and valuable products) and reselling them for profit. Maybe you’re obsessed with a specific topic and want to start a blog that can one day bring in advertorial and affiliate income.
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