The basic math behind getting subscribers is that visitors are more likely to stay, when seeing the that topic, they initially came for, is covered in more depth through a series of blog posts.
One way of suggesting similar posts to the reader is, of course, the taxonomy system. That is, by tagging similar posts with the same keyword. This method has four disadvantages:
- It has to be done manually.
- Tags are grouping elements and only work well for medium sized groups. Introducing new tags that will only be used for a handful of posts will inevitably lead to a cluttered tag cloud.
- Tags have a click distance of at least 2. That is, in order to find similar posts, the user first has to click on the tag in question and then sift through the list posts, tagged with that keyword.
- Tags are less meaningful than titles.
A better method for suggesting similar posts to the readers would be to actually show the titles of these below the post, they are currently reading. This can easily be done using the Similar Entries module.