I do remember you mentioning that & how it was your ticket to exit softly and give you time to build the passive income side. Most likely when I do exit it will either be through a sale of the business which would come along with a employment contract or if a worthy successor(s) can take it over, then the business is just another annuity throwing off income. Anyway, I’d enjoy writing a guest article after I survive the next few weeks of work and weddings.
Real Estate: I currently own one rental property in San Francisco which I bought in 2003 (2/2 condo), one vacation rental in Squaw Valley, Lake Tahoe (2/2 condo), and my primary residence. Real estate is my favorite asset class to build wealth because it is easy to understand, tangible, provides utility, and rides the way of inflation. I recommend individuals try and get neutral inflation by buying their primary residence as young as possible. The power of inflation is just too hard to counteract.
Lending Club went public in 2014 and is now worth about $1.7B. They advertise P2P lending returns of over 7% for well-diversified portfolios of over 100 notes. I’ve personally been able to achieve a 7.4% annual return over the past two years in a completely passive way by investing in A and AA notes. Others have achieved a 10% annual return through relatively minimum effort. https://i.ytimg.com/vi/gOikEE3Xibw/maxresdefault.jpg

Investing in real estate: Investing in real estate offers more passive income cash potential - but more risk - than investing in stocks or bonds. You'll need substantial amounts of cash to invest in buying a home -- it usually takes 20% down to land a good home mortgage loan. But history shows that home prices usually rise over time, so buying home a for $200,000 and selling it for $250,000 over a five-year time period, for example, is a reasonable expectation when investing in real estate.
While it is important to find something that you love to do and turn it into a money making business, you do have to be cognizant of the return as you pointed out. There are many opportunities that I found and tried out that at the time seemed great. But when I took a step back, I realized that I was working a lot for very little income whereas other things I love doing brought in much more money.
You know the fantasy: write some ebook (or better yet, hire freelancers in Mumbai to research and write it for you at $.20/word!) on some niche topic, set up AdWords and Facebook campaigns targeted to the right keywords (you can hire those Mumbai guys to do your keyword research too), put up a cheap landing page (with copy written by... guess who!), press "Go!" on the PPC campaign, and voilà. . . just wait for the money to roll in while you sleep!

Creating passive income is the key to retiring, especially retiring early. If you want to retire early with the stock market you will have to save a huge amount of money, because that money has to last so long and retirement calculators depend on you using your investment to fund your life. With passive income you will have income coming in as long as you own the investment, without every eating away at the principle invested. Creating passive income may take more work than investing in the stock market, but I think it is well worth the extra effort!