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.
Email is a relationship-builder with your potential customers. You want to send them a balance of useful information related to your niche, perhaps an email newsletter, as well as marketing messages, like a sales email, asking them to buy a product on sale. The free information you’ve provided helps them come to know, like, and trust you… which makes it more likely they’ll buy a product.
When you have your own product or service you hold a lot more control of the funnel from beginning to end. But I’ve worked with many marketers to help them better control the best affiliate marketing funnel with banner ads, blog posts and social media. Once people move from those elements to the sales page – I help them control their message and email marketing campaigns and everything behind the scenes.