User blog comment:Sannse/Important Updates on Wikia’s New Look/@comment-75.71.39.16-20100930192507/@comment-400262-20100930203103

It has nothing to do with favoritism, it has to do with the simple fact that such a big wiki has a lot of leverage when making deals with Wikia, compared to smaller wikis. It's the same reason that WoWWiki and Memory Alpha still have their own domains. They are the ones that are able to make serious threats to Wikia. If it was up to Wikia they would all be using monaco now and the new look soon, and be subdomains of wikia.com. That's what Wikia would like, but the communities of those wikis have been able to resist (except for uncyclopedia that lost their .org url). Wikia wants to be able to make the most money they can, so they would like to use their ad-friendly skin(s) everywhere and make the wikia.com domain as large as possible to attract advertisers.