Let’s continue the vintage BMW idea. Old cars obviously require quite a lot of maintenance. Many people will buy a “fixer upper” with the intention of spending their spare time repairing and restoring it. There’s a very obvious market here: a guide to restoring different BMW models. Depending on your knowledge, you could produce detailed guides for the three or four most popular models and sell them. Not everyone restoring a car will buy them, but some probably will.

It’s obvious that stocks outperform real estate in terms of capital gains, but I would like to see S&P compare to Real Estate in SF, Manhattan, LA. Our house in NC was $80,000 20 years ago. It’s only $150,000 now. Same house in Santa Monica went from $200,000 to $1.8 million. People who happen to bought real estate in major metropolitan would have a natural positive association with real estate investment.

There are a couple of problems with direct investment in real estate though. It’s expensive to buy even a single property, a minimum of tens of thousands of dollars, and there’s no way most investors can build a portfolio of different property types and in different regions to protect from those risks when you have all your money in just one or two investments.
We usually think of Craigslist as a place to buy and trade random stuff, but Craigslist can actually be a great opportunity to sell your services online to an active and engaged audience. Simply check the “jobs” section and “gigs” section for specific cities and see if anything matches your skills. The great thing about Craigslist is that it is one of the highest converting traffic sources on the internet (think active buyers) which can mean more opportunities at higher pay.

However, investing in passive income streams isn't as easy as it looks. Most online passive income strategies, such as e-commerce, are effective and profitable only after you have built up a substantial following. And they take a lot of time, and sometimes, money, to make them work, unlike passive investing in low-cost index and other funds in the stock market.

I knew I didn't want to work 70 hours a week in finance forever. My body was breaking down, and I was constantly stressed. As a result, I started saving every other paycheck and 100% of my bonus since my first year out of college in 1999. By the time 2012 rolled around, I was earning enough passive income (about $78,000) to negotiate a severance and be free.

If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.