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.
The moment you step into the world of affiliate marketing, the key skill needed to make you succeed is expertise in digital marketing. While it may take some time for you to figure out whether email marketing works for you, or is it SEO, it is a good idea to begin by knowing all fields of digital marketing and then deep diving into one particular subject. You will learn about topics including Facebook Marketing, Twitter Advertising, Quora Marketing, Google Adwords, Google Analytics and even EMail Marketing, SEO Fundamentals as well as WordPress.
Always disclose your affiliate relationship. Most visitors will probably understand that graphic ads will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.