Contextly's related content recommendations use a constantly evolving algorithm that takes into account story similarities, entities and connections between stories.
For sites that have over 250 posts, Contextly optimizes the algorithm for every post. Which is to say each post gets its own custom and constantly evolving algorithm.
The algorithm is testing for the best combination of strategies that boost engagement, not clickthroughs.
Writers and editors play an important role in recommendations. Humans are far better than machines are at context so we make it dead simple for writers to choose related links for stories.
You can do this two ways:
One: Add links to older posts in the body of your story. You can use our Single Link button in the Visual editor to do this (Don't worry if you hand-code them, we'll pick up on them,too).
Two: Use the big Choose Related Posts button. This doesn't add links in your story but your choices will show up in the related module.
Our algorithms use these human-created connections to make smart inferences about what other posts might be related, and to know what older posts should point to a new post.
Choosing related stories isn't required, but it is extremely useful for both your readers and our algorithms.