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.
You should also make sure you aren't competing with your own affiliates for eyeballs. Any marketing channels you're using, such as search engines, content sites or e-mail lists, should be off limits to your affiliates. Put marketing restrictions into your affiliate agreement and notify partners immediately. It's your program--you set the rules. Or, if you prefer, you can let your affiliates run the majority of your internet marketing.