Since the emergence of affiliate marketing, there has been little control over affiliate activity. Unscrupulous affiliates have used spam, false advertising, forced clicks (to get tracking cookies set on users' computers), adware, and other methods to drive traffic to their sponsors. Although many affiliate programs have terms of service that contain rules against spam, this marketing method has historically proven to attract abuse from spammers.
First things first, choose a niche. You should choose something which interests you, you don’t mind learning about, or have the ability to pay someone else to write about. Consider the potential costs carefully before delving into something which you know absolutely nothing about. Another important aspect is to be confident that it will be a lucrative niche to work in. There needs to be an abundance of products to promote, and the commission levels need to be significant enough to give you a good profit each time a sale is made.
Not necessarily, but a blog is really the best promotional tool. With that said, you can always use methods such as PPC or advertising to promote a product. This is another popular method to grow in affiliate marketing. For me, the best way to make the most out of affiliate marketing opportunities is to have a blog. Learn how to start a blog here.