There are lots of reasons one can fail as an Amazon (or CJ, Linkshare, ShareASale, etc) affiliate. However, some reasons are more obvious than others.

Listed below are some of the more major reasons I’ve seen for folks failing at affiliate marketing (especially Amazon). 

You are targeting products that you can’t possibly rank for…

So you want to earn monster commissions in the HDTV niche eh? Well, so does everyone else. If you rely on organic search for traffic, stop promoting "Best Sellers" and popular items. Everyone and their grandmom is doing this. Unless you can rank above the fold on page one in Google, your product reviews just aren’t going to be seen. Instead, go after the less-competitive products in the same niche.

You are spending more time on backlinks and less time creating content…

If you need to spend 5 hours per day building backlinks just to rank your product reviews, you are really making life difficult for yourself. There is so much low-hanging fruit to chase that I never understood why people chase generic, high-traffic / high-competition terms that require such effort to rank for. Target lower-competition stuff and spend more time writing content for your site and less time trying to rank. You will have far fewer grey hairs and results will be realized more quickly.

You are not targeting "buying" phrases…

Sure, the term "HDTVs" will get you a TON of traffic (if you can even rank for it). However, how many people who are searching for that term are going to actually buy anything anytime soon? I’ll answer for you – not many. Stop targeting "traffic" and start targeting "buying" traffic. Think about what terms you would search for when researching something you were ready to purchase. Those are the terms you should be targeting.

Your content is not compelling…

If I am searching for information about a product I am ready to buy and I land on your site and I’m immediately greeted with a wall of text, I’m clicking my "back" button. For Pete’s sake, break it up! Add some images! Add some paragraphs! A wall of 800 words just isn’t appealing to me. By the same token, please don’t tell me 4-slice toasters are great or that I can toast more slices of bread faster. Stop with the mundane details. Give me something useful. 

Oh, and PLEASE don’t just repeat what Amazon is saying. Chances are VERY GOOD that I’ve ALREADY been to the product page on Amazon. I already know what they are saying about it. At least give me YOUR opinion on what Amazon/others are saying about the product. Simply parroting what Amazon already said is not helpful to me.

You are promoting things that people simply do not buy online…

I realize that "anything" can be bought online. That said, some things just aren’t as conducive to online shopping as other things. Some things are simply too expensive for many to trust buying online. Some stuff requires the buyer to try it on. Some stuff is just cheaper at a brick and mortar. Think about what you are trying to promote and ask yourself if people really buy it online.

You are promoting things that you know nothing about…

I just thought of this one. Please folks, know something about what you are promoting. If you know nothing about HDTVs, either learn about them first or simply do not promote them. It becomes painfully clear in your wording when you have no idea what you are talking about. Your visitors can tell.

I’m sure there are others and I’ll add them as I think of them. That said, address the few mentioned above and you will give yourself a much better chance of success.