Building a smartphone or tablet app requires a fair amount of technical expertise, but it can pay off handsomely if successful. It doesn't have to be particularly complex or chock-full of features either; a simple one that solves a problem or is entertaining enough to attract users works fine. You never know what may suddenly become popular. For example, the minimalist game Flappy Bird was such a craze that at one point its developer was earning $50,000 dollars a day through in-app advertising. Of course, expecting a success like that is foolhardy, but one can always hope.
In 2012, even I wrote a 150-page eBook about severance package negotiations that still regularly sells about ~35 copies a month at $85 each (2nd edition for 2017) without any effort. In order to generate $2,975 a month or $35,700 a year in passive income as I do now, I would need to invest $892,500 in something that generates a 4% yield! To earn $10,000 a year in passive income would therefore need roughly $250,000 in capital.
I wish I had more time to put into real estate. Given the run up since 2012, I may even be interested in selling my condo that I currently rent out. I need to get it appraised to really see what it’s worth, but I think conservatively it’s gone up ~50%, although rent is probably only up ~10% or so. I am bullish on rents going up in the future… mostly in line with inflation, or perhaps even slightly faster due to constricted credit and personal income growth which should provide a solid supply of renters. At this point, I just don’t want to manage the property. I’ll probably look into a property manager as my time is likely worth turning it into a nearly passive investment.
1) Save Like Nobody Owes You Anything. Passive income starts with savings. Without a healthy amount of savings, nothing works. Your overall “Money Strength” will be an F- if you do not build a financial nut. In our current low interest rate environment, you must save even more than before. It’s important to also realize that the savings I am referring to is AFTER-tax savings. You need to save money after contributing to your 401k and IRAs since you can’t touch pre-tax retirement accounts without a penalty until 59.5. Ideally everyone should max out their pre-tax retirement funds first, but if you don’t have enough funds and want to retire earlier then a decision to have more accessible post tax money will still work.
According to Uncle Sam, you need to be "materially involved" in an enterprise to earn active income. With passive income, it's just the opposite, as the IRS deems you to be earning passive income if you're not materially involved with a profit-making enterprise. By and large, expect income to be taxable if you are engaged in a passive income enterprise. You will need to report earnings to the IRS.
I have a total of three CDs left. There is no way in hell I’m selling them after holding them for 4+ years so far to take the penalty. The CDs are for 7 years. That would be completely counterproductive. As a result, I feel very stuck with ever getting my CD money back if I wanted to. If the CDs were for just 1 or 2 years, I agree, it doesn’t matter as much. But combine a 7 year term with 4%+ interest is too painful to give up.
"Rental properties provide a source of passive income and the possibility of overall appreciation of the property with tax advantages," Lou Cannataro, partner at Cannataro Park Avenue Financial, tells Bustle. "Our generation and those to follow will not have pensions, and social security is 'iffy,' at best. Rental properties can provide that constant income (people always need a place to live) that is not directly tied to the marketplace and one cannot outlive."
Peer-to-peer lending ($1,440 a year): I've lost interest in P2P lending since returns started coming down. You would think that returns would start going up with a rise in interest rates, but I'm not really seeing this yet. Prosper missed its window for an initial public offering in 2015-16, and LendingClub is just chugging along. I hate it when people default on their debt obligations, which is why I haven't invested large sums of money in P2P. That said, I'm still earning a respectable 7% a year in P2P, which is much better than the stock market is doing so far in 2018!

The reverse can also be expected unless the rents rise too.  This rental increase might occur if we imagine interest rates are rising because the economic environment is improving.  At present, it is widely expected that rates will rise ever so slowly over many years.  Indeed the US has been looking for the courage to do this over recent months and they may start rising there soon.