This is a very common way to promote offers. For example, you will often see a blog post with links to certain products or services. If the reader clicks through and makes a purchase, the blog owner will make a commission. These in-text links blend in with other content on your site and are a great way of promoting an offer within your content, without being over-the-top salesy with banners.
A more complex system, pay per lead affiliate programs compensates the affiliate based on the conversion of leads. The affiliate must persuade the consumer to visit the merchant’s website and complete the desired action — whether it’s filling out a contact form, signing up for a trial of a product, subscribing to a newsletter, or downloading software or files.