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.
17. Amazon – Have you heard of FBA? It stands for “Fulfilled by Amazon” and it’s getting pretty popular. Basically, you buy products (in bulk is best) and ship them to Amazon for them to store. When your products sell, Amazon packs them up, ships them out and sends you the money (after taking their cut). There are people making a full-time living from FBA, while others just do it for some extra money.
Referral fees aren’t just for the products you recommend. Perhaps the coolest thing about the Amazon Associates program is that you receive credit for any sale associated with your affiliate link for 24 hours. So, if a customer visits the page of the product you recommended, but then goes on to purchase five more eligible items during that same visit, you will receive a portion of that entire sale.