Creating a unique tracking ID for an Amazon link is easy. Simply log in to your Amazon affiliate dashboard, click “Account Settings” at the very top on the right, then click “Manage Tracking IDs”. From there you can make a new tracking ID so you can track which web page/campaign sold what. You can learn more about using Amazon’s Tracking IDs here.
I would like to add that for information products, a lot of the time it’s pretty easy to rank for “information product review”. I recently did a review of a popular ebook that is a month long discipline program. I went about it by doing the actual program and documenting everything. At the end of the month I wrote up a 2700 word article summing up the whole experience.