Residual income is income that keeps coming in month after month, year after year, from work you do only ONCE. One type of residual income is earned when a product is sold and the customer reorders the same product again and again requiring no additional effort. This type of order is referred to as an auto-ship. This business volume is what your recurring income is based on, so the more affiliates (or customers) on auto-ship in your network, the higher your residual income will climb.