Affiliate Marketing, IMHO, should be a part of every Online Business owner's arsenal ... and is usually the first order of business employed by the newbie Online Business owner, which is fine.
However, I can't stress it enough that you should have a full understanding of Affiliate Marketing, itself, methods of promotion, and most important of all the legalities involved including the terms set forth by the merchant behind it and the platform they are using to market and sell the product/service.
Not trying to scare anyone or throw a wet blanket on their desire to make money Online promoting Affiliate Programs ... it's a wonderful Marketing option, when done right. Just make sure you have all your ducks in a row, as I mention above, to make the most of your efforts.