And you probably contribute to this trend on a regular basis. The truth of the matter is, Microsoft make more money from the sale of upgrades than they do from selling new versions of the products. And as long as they continue to make upgrades, people will continue to purchase them. This is an example of what is called residual income.
Purchases made after the initial sale can provide a continuous and growing source of income.
To create a residual income you must create follow on sales. Follow on selling is based on the idea that it is easier to sell to an existing customers than it is to get new customers. This is not a difficult concept but a large number of Internet marketers seem to overlook it completely. First you must evaluate your product line. Identify the products that are natural compliments of one another.