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.
Become an Amazon Associate and then use Keyword planner to find an in-demand niche: With more than a million different products to choose from and up to 10% commission the sales you drive, Amazon’s affiliate program is a great place to get started. Browse their available products and see what connects with you. Or take it a step further and use Google’s Keyword Planner to quickly check how many people are searching for a specific term. With affiliate marketing, the more relevant traffic you can pull in, the more you’ll make off your site.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
The terms of an affiliate marketing program are set by the company wanting to advertise. Early on, companies were largely paying cost per click (traffic) or cost per mile (impressions) on banner advertisements. As the technology evolved, the focus turned to commissions on actual sales or qualified leads. The early affiliate marketing programs were vulnerable to fraud because clicks could be generated by software, as could impressions.
Last but not least, you can also earn money online by building an online community, although the monetization strategies you can pursue will vary a lot depending on your goals. You can build a community with a blog, for example. You can also build an online forum and charge people for membership. You could even build up a Facebook group and use your influence there to sell and promote products.
Create a killer course experience: With your course validated and in the works, you need to figure out how people will take it. Most course creators choose to host their courses from their own websites. This way, they get all the value of bringing customers back to their site on a regular basis. I host my own courses from a subdomain on my own site so I can easily add more. The course experience is incredibly important as well. And after trying most of the solutions, I highly recommend Teachable—an online platform designed specifically for courses.
I think content marketing is absolutely huge for affiliate’s, especially going into 2016, I think it will increasingly become something that will have to be adopted to gain domain trust, authority and good SERP rankings. Google loves quality content and if you want your website to stand the test of time, white-hat SEO is a must and content marketing is king!