4) Treat Passive Income Like A Game. The only real way to begin your multiple passive income journey is when you are making active income. The initial funding has to come from somewhere. Hence, treat passive income as a game that has various levels. If you fail to achieve one level, it’s not the end of the world since you still have active income and can restart. Furthermore, a game is meant to be played with integrity. Using shortcuts (non passive income streams), someone else’s income as a supplement (spouse), or one-offs (capital gains) does not count. The primary purpose of any game is to bring enjoyment to the player and beat the boss.
That income is considered residual income because as long as the apartment is rented and the rent is collected, the income is earned without additional effort. The effort came when the property was purchased and a tenant was found. Each month after that, the money automatically is paid without buying the apartment again or finding the same tenant each month.
I’m a 45 year old business owner who also has focussed on diversifying my income streams. I have a short term vacation rental in Florida that I bought for $390k in 2012 and net rental income for the last three years has been growing steadily. 2015 I am at $70k gross right now but should end up at $80-85k with net around $45k plus we use the place about 35 nights a year.

Residual income is the amount of net income generated in excess of the minimum rate of return. Residual income concepts have been used in a number of contexts, including as a measurement of internal corporate performance whereby a company's management team evaluates the return generated relative to the company's minimum required return. Alternatively, in personal finance, residual income is the level of income that an individual has after the deduction of all personal debts and expenses have been paid.