You can easily make it ‘customizable’ by creating a few different variations of the project. I’ve sold a customized personal investment plan on the site and deliver one of four different plans depending on the answers to questions sent by buyers. It involves almost no work after you’ve created the project so it’s an excellent source of residual profits.
Charge a monthly or annual fee to offer members access to exclusive advice or products. Sell your expertise through exclusive podcasts, offering live FAQ sessions through Skype, or forums. You may want to try selling a monthly subscription to allow users to sample new products, similar to a book club. Frequent interaction increases interest and helps build membership through word-of-mouth.

This may be a method that is unusual. Drive traffic to your lens the same as you would your blog. Link to your lens on social media platforms, like Twitter. The more people that know about the lens, the more that are apt to visit and purchase. The lens can also be used to promote products on e-bay or CafePress. Write a short description of the product and its unique uses and sell away.
5. Resource pages: Regardless of your niche, your readers are likely interested in the products and services you use to do whatever it is you are trying to teach them to do. Let’s say you share amateur photography tips. Your readers probably want to know what kind of camera and lenses you use, your preferred editing software, where you learn new skills, products you have created, and more.
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.