You'll also need ecommerce software, fulfillment software, worry about warehousing, customer service and refunds. But that's not all. You'll also need traffic. Think search engine optimization, Facebook ads, and other social media campaigns. It is hard work, especially on your own. You could opt for Amazon's platform, which might be an easier route. But, then again, at the end of the day, this is a serious business, which could produce significant profits. So you're either all in or you're not.
Affiliate marketing is a big and profitable industry that covers a wide spectrum of topics and fields. If you have got an interest in fitness, you can make money promoting fitness videos or courses e.g. videos to loss your weight. In fashion wear, you can earn commissions by recommending friends to clothing or t-shirt of companies which are offering affiliate programs.