Great post , I do read a lot of the Nichehacks articles and this one is so true. At the moment I am in a niche I'm passionate about and yes although I am primarily using Amazon to monetize my site, I will be branching out to use other methods very soon. It frightens me to think the plug can be pulled at any time! I intent to use other affiliate programs as well as Amazon, maybe Google Adsense, I'm not sure yet, some digital products and also to build an email list.
2. People Buy More than One Item the great thing about Amazon is that you dont just earn a commission on the product that you send people to, but anything that they buy once theyre at Amazon. You earn a commission on anything a person buys within 24 hours of you sending them to Amazon. One out of every four shoppers buys more than one item per session.
There are many ways to get people onto your list. Lead magnets are one such resource. For example, you can build ebooks, checklists and cheat sheets. But you can also do content upgrades, such as PDF versions of an article with added resources in them, four-part video training series, and more. Think about your audience and what you can offer them to better serve them, then treat them with some respect and you'll eventually reap the rewards.
The other type of Amazon affiliate link I use is when I’m mentioning a product in passing and/or a new product is announced. For example, when Nikon announced the Nikon D300s we immediately posted about the news because it was a notable and anticipated camera announcement. The camera was not yet available in stores and we were not able to get a review sample yet – but it was available for Pre-Order on Amazon so we linked to it.
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. 
Consider your expertise. If you take the time to reflect on your experiences, you will realize that you have more knowledge about which to write than you might think. Begin by listing three assets that define you, such as your profession, a special hobby or a personality trait. Next, list three things that inspire you, such as religion, education or charity. Finally, list three of your dreams, such as getting married, traveling or spending more time with your children. These three lists should give you many ideas of topics about which you can write.
Understand how a niche website works. A niche website focuses on very targeted, specific information. The content must be specific, useful and interesting to your target audience. Successful niche websites get anywhere from 1,000 to 10,000 visitors per month. You build content on a particular keyword, and you make passive income with Google Adsense or through affiliate links.
Find work. When you first start out, you may have to accept work writing about a topic you don’t find all that interesting. You must keep an open mind and be willing to accept work that may not be in your desired field. However, as you continue to write, you not only learn about more topics, but you also build your reputation. With time, you can be choosier about assignments you want to accept.