With $200,000 a year in passive income, I would have enough income to provide for a family of up to four in San Francisco, given we bought a modest home in 2014. Now that we have a son, I'm happy to say that $200,000 indeed does seem like enough, especially if we can win the public-school lottery to avoid paying $20,000 to $50,000 a year in private-school tuition.
Leveraging the internet to create, connect, and sell is something every creative person should attempt to do. The only risk is lost time and a wounded ego. You can start a site like mine for as little as $2.95 a month with Bluehost and go from there. They give you a free domain name for a year. Forget all the add-ons. Not a day goes by that I’m not grateful for my site.
I have not. While I am intrigued with the possibility of making online income, it seems to be less passive then how I want to spend my time. Regarding your blog / site, you have done quite well for yourself. However, you have to keep pumping out content or your site would eventually go out of business. That sounds like more of a commitment then I would want. Regarding your book sales, it is probably relatively passive now, but certainly was not when you were writing the book. Now if you love it, great. Just not for me.
If you're looking to get started in real estate, look at a crowd funding solution like RealtyMogul. It works similar to LendingClub - you commit as little as $5,000 towards a property. When the property is fully funded, you become an owner, and will receive your share of the earnings and appreciation in the property.  Check out RealtyMogul to learn more.