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.
Just like to add 1 additional "CON" to the list of Pros and Cons of Clickbank. Their rule on paying out the commissions earned. You must have 5 sales all from different credit card accounts before they will pay you what you have earned. That flat out sucks!. Affiliates work hard to get even 1 sale and because of Clickbanks rule, lose that money over time if they cannot get another 4 sales, the commission keeps reducing steadily if 4 more sales are not forthcoming. Clickbank has got to change that rule, which many feel is illegal!. A sale, is a sale, and the commission must be paid out. Basically, Clickbank is "Ripping-Off" affiliate marketers.
As someone who's been immersed in a number of online industries for quite some time, I know a thing or two about what it takes to succeed in this arena. However, just like you, I started at ground zero with little knowledge, but a great deal of passion. What I learned along the way were some invaluable lessons from failure that hurt at the time, but helped immensely in the grand scheme of things.
If my piece of content is so unique and valuable around hiking backpack recommendations, that other reputable outdoor websites are willing to link to it and build the page’s authority, then I’d have a very real opportunity to rank high in organic search for these search terms (meaning, my page will come up first when someone searches for hiking backpacks).