You don't have to be Paul McCartney to rack up residuals. You might own properties that you rent out even though you're not a Realtor. Maybe a blog you started took off, and while you no longer work there, you still collect part of the profits. Or perhaps you're a serial entrepreneur who creates companies and moves on. You, too, are earning residual income.

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.