Commission Junction is an affiliate marketing network. You can join as an affiliate or a merchant. Affiliates promote products or services from merchants in exchange for a commission. You can sign up for free and browse through various programs. Merchants offer different commission structures and products to promote. You can choose programs that match your niche and audience. Once you join a program, you will receive unique affiliate links. You can promote these links through websites, blogs, or social media. When someone clicks your link and makes a purchase, you earn a commission. Commission Junction helps track your sales and earnings.