Music may perform better than books and other products, mainly because you can listen to the clips of an entire album in roughly 10 minutes and get a good enough feel for it without buying it to write a short review. If you have another topic that you're passionate about, great, but make sure you have a unique angle on the topic. People can get reviews about a lot of those consumer products anywhere. You need to give them a reason to visit your site.
Affiliate marketing was a very early implementation of marketing strategy via the web. Several different industries are associated with its origins (such as flower delivery, music and even adult entertainment) but it is difficult to track an exact origin, partially due to its rapid expansion concurrent with the rise of the world wide web in the 1990s.