But in a way, when you link to a previous chapter, it's like you copy it in another branch.
In that case, most of the times, you would still get a few likes for it, even if it is exactly the same. I've seen it many times.
So, what's different? You give your chapter a second chance for visibility, hence likes get divided by two.
That's not quite how it actually works out, though. Consider two situations with link chapters.
One is a simple story with a main branch, e.g. Introduction-chapter A-chapter B-C-D and another that branches off chapter A and rejoins it at C, that is, A-1-2-(C). Imagine a reader reads the main branch from the Introduction to D, then goes back to A and reads the secondary branch up to D. If the stories are linked so that the second branch is laid out like A-1-2-link to C, then the reader is liking the Introduction, A-D, and 1 and 2. If chapters C and D are just copy-pasted over, such that the secondary branch is A-1-2-3-4, where 3 and 4 are identical to C and D, then the reader is liking the Introduction, A-D, and 1-4.
In the first scenario, with a link chapter, the reader increases the story's like-to-chapter ratio by 0.875 and the total likes by 7. In the second, without the link chapter, the reader increases the like-to-chapter ratio by 1.0 and the total likes by 9. Obviously that's not an extreme difference, but it is a difference, and when you're using many link chapters and have many readers it significantly impacts your story's stats.
The other situation is with a game mode story. Let's say you have a hub called The Village, and chapters branching from it called Visit the Blacksmith, Go to the Tavern, and Speak with the Town Crier. These might be just one chapter long or be a twenty chapter storyline; they might be linear by themselves or have several additional choices throughout. Regardless, at the end, they each link back to the central hub. When you go back to the hub, the content of that chapter is completely different based on whether you did those activities and which one you did most recently. This isn't particularly difficult to achieve nor unusual with game mode.
The key here is in the hub. It doesn't matter if you enjoy each different possible text configuration for the chapter, as you can only like it once. This means the link chapters aren't actually making the hub chapter more 'visible', because you can't even use the link chapters unless you've already seen the hub chapter. Alternatively, you could make a new hub chapter for every possible configuration, but then the need for link chapters evaporates because you can just put each hub at the end of its respective branch instead. There is no way that use of link chapters here can actually give the reader direct access to a chapter they haven't already seen; this can only be achieved by reducing use of link chapters, or alternatively, by increasing them unnecessarily and having a net negative impact on your like-to-chapter ratio.
In both of these situations, the author is effectively rewarded for not using link chapters when they would be beneficial, or by using them in an untidy and inconvenient manner.
