Promote products that are stepping stones to products you will create in the future. This is a bit more advanced, but is a great way to think ahead. Amy Porterfield suggests thinking about the first thing your followers will need in order to get started with what you provide. For example, I teach people how to blog, so the first thing they need to start a blog is hosting. That’s why I am an affiliate for hosting.
You can sell your ebooks through Amazon's Kindle program or Apple's iTunes Connect, which gives you access to a large majority of the digital-book reading market and the barriers for entry are incredibly low. You don't need to invest lots of money to make this happen, but you do need to invest lots of time, not only in writing the ebooks, but in marketing them as well.
It's a little awkward, so we'll get straight to the point: This Sunday we humbly ask you to defend Wikipedia's independence. We depend on donations averaging about $16.36, but 99% of our readers don't give. If everyone reading this gave $3, we could keep Wikipedia thriving for years to come. The price of your Sunday coffee is all we need. When we made Wikipedia a non-profit, people warned us we'd regret it. But if Wikipedia became commercial, it would be a great loss to the world. Wikipedia is a place to learn, not a place for advertising. It unites all of us who love knowledge: contributors, readers and the donors who keep us thriving. The heart and soul of Wikipedia is a community of people working to bring you unlimited access to reliable, neutral information. Please take a minute to help us keep Wikipedia growing. Thank you.