Now as to your comment on traffic it is true, traffic is important. But the truth is, acquiring traffic is easier than converting it. Plus we have many posts dedicated to traffic generation on this blog. Simply check this post, this post or this post. But must importantly, the reason why people struggle with traffic is that they try to promote a sales page or a heavily biased piece of content. Nobody wants to share that, nobody wants to link to that, and as a result you don't get traffic and blame your lack of success on traffic (like you did in your comment above).
The phrase, "Affiliates are an extended sales force for your business", which is often used to explain affiliate marketing, is not completely accurate. The primary difference between the two is that affiliate marketers provide little if any influence on a possible prospect in the conversion process once that prospect is directed to the advertiser's website. The sales team of the advertiser, however, does have the control and influence up to the point where the prospect either a) signs the contract, or b) completes the purchase.
Affiliate marketing is referral marketing in a sense, but instead of using word of mouth, every referral is automated online. Where referrals usually come from friends or family, sales that come from affiliate marketing may have no personal relationship with the person who referred them. That’s because anyone can click a link and be directed to a product on your site without the affiliate’s knowledge.
You'll also need ecommerce software, fulfillment software, worry about warehousing, customer service, refunds and so on. But that's not all. You'll also need traffic. Think search engine optimization, Facebook ads, and other social media campaigns. Sound like a lot of work? Sure, it is. Especially if you do it all on your own. You could opt for Amazon's platform, which might be the 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.