Board Thread:Support Requests - Designing Your Wiki/@comment-32590715-20200511203252/@comment-9605025-20200511204740

It isn't just about ad space. Fandom wants all the wikis to have some level of similarity. The reason is that "data shows" this is good for the user experience and that a good user experience mean more views (and thus more revenue). As for why these features are in the side rail to begin with, well I am sure Fandom would give you a similar reason. They would probably argue that "data shows most users" either like having things like "popular pages" or that having such a feature at least increases the number of pages visited. In some cases, the top entry in the "popular pages" is not actually to another page on the wiki but to a partner's promotional site or an article on www.fandom.com.

Of course, I have nothing to back this up as everything they do is the result of "data" that they don't want made public. A similar example to the right rail could be Discussions. A lot of users here on CC believe them to be majorly inferior (feature wise) to Forum. However, Fandom's "data" shows that "actually, most users" prefer and participate more with Discussions than Forum (mostly because it is mobile compatible) and that the features CC users complain are lacking are "unnecessary".