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.
In the last 10 years, ShoutMeLoud has inspired millions of lives around the globe to help them earn passive income via affiliate marketing. It would not have been possible if I had not quite my call-center job to pursue my passion. When I think about this, I find it amazing as for how my life unfolded when I took the courage of starting something of my own.
Another way to find this information is to do a simple Google search. For example, one could place the following phrase into Google Search: “(product name) + affiliate program”. (Replace “product name” with the name of the product you are promoting.) There is an interesting chrome addon called Affilitizer is available which makes this process easy.