At the time, I had a ton of people reaching out wanting to hire me (I ranked my self #1 in Google for WordPress SEO Consultant, WordPress SEO Expert, many other good keywords). Unfortunately I struggled with basic things you need to run a service-based business… keeping track of clients, time management, and making sure I was charging clients for my time (and getting them to create content which often seemed impossible).
In some instances — like when the affiliate link is embedded in your product review — a single disclosure may be adequate. When the review has a clear and conspicuous disclosure of your relationship and the reader can see both the review containing that disclosure and the link at the same time, readers have the information they need. You could say something like, "I get commissions for purchases made through links in this post." But if the product review containing the disclosure and the link are separated, readers may not make the connection."
Amazon's commission rate is pennies from each dollar of merchandise that you sell. What many people don't know is that there are affiliate opportunities out there that pay commission rates that are much more favorable, from $20-$100 (and even more). Browse affiliate networks like Commission Junction, Share-a-Sale, Rakuten and Ejunkie for opportunities and their general commission rate.