From what he describes, creating passive income definitely does not sound easy. It requires a serious ramp-up -- often requires 80- to 100-hour workweeks in the beginning, says Flynn. But once up and running, and depending on the content, some sites take fairly minimal maintenance. Green Exam Academy, the LEED exam study site he launched in 2008, takes just him four to five hours a month to maintain but brings in $250,000 annually.

That $200,000 a year might sound like a lot to you, but the median home price in San Francisco is roughly $1.6 million or almost eight times our annual passive income. For a family of three in 2018, the Department of Housing and Urban Development declared that income of $105,700 or below was "low income." Therefore, I consider us firmly in the middle class.

* I use Personal Capital to track all my finances in one place. It’s much easier to use their free software to follow 28 accounts on one platform than to log into various accounts to check my balances. They’ve also got great tools for x-raying your portfolio for excessive fees, recommending a more optimized asset allocation, and planning for retirement with their Retirement Planner.