This is because as you practice affiliate marketing, times shall come when you will need to make text links, image links, video links, embed videos or audios into a webpage, format articles or insert third party scripts like AdSense, Google analytic, CPM advertising scripts into your sites etc. A basic knowledge of HTML will help you a lot.
Learning email marketing: When it comes to making money with affiliate marketing program, your greatest asset will be a list of the email addresses of your email list customers and potential customers. This is because people hardly buy something the first time they visit a sales page. Another reason is that you can offer your list with multiple products in your niche. Therefore, you have to know how to get their email addresses, how to use an autoresponder, how to create wonderful opt-in forms etc.
Having a website: You can make money without a website, but if you're serious you have to get a website. You can either build one yourself or outsource it at freelancing sites. You can also use free blogs or free website templates. For people still at the basics of affiliate marketing, using free resources is recommended since they're still testing the waters. Generating Traffic: To make money with affiliate marketing, you need traffic. Without people coming to your website, you can't make a sale through your affiliate links.