This is a huge problem with Wikia. Wikia has a relatively high pagerank. Sometimes, because of Wikia's often-abusive policies, communities will decide to move their wiki off Wikia and host it separately.
But Wikia will refuse to remove the original wiki even if all the contributors want to move it, in order to maximize advertising revenue. This means that it's nearly impossible to get the new wiki to rank highly on Google, even if all links across the internet are changed to point to the new wiki, because Wikia's pagerank is so high that Google deems the new one to be a "copy". This is why Wikia moved all their wikis to subdomains: in order to piggyback on the pagerank of the main site.
As a result there are a ton of long-dead wikis on Wikia that still get more search traffic than the active equivalent. Obviously this hurts users, since they get long-outdated information as a result.
In short, once a wiki is placed on Wikia, it's basically impossible to ever move it anywhere else because of Google's anti-duplicate biasing.
I assume you're saying that the Wikia admins will prevent the community from deleting or overwriting content with a pointer redirecting to the new place? This does seem extremely likely if there's significant search engine traffic and ad revenue.
Yes. Now imagine if you had a blog on Blogspot and you wanted to host it on your own site instead -- and Blogspot prevented you from deleting your posts because they brought Blogspot good ad revenue?
But Wikia will refuse to remove the original wiki even if all the contributors want to move it, in order to maximize advertising revenue. This means that it's nearly impossible to get the new wiki to rank highly on Google, even if all links across the internet are changed to point to the new wiki, because Wikia's pagerank is so high that Google deems the new one to be a "copy". This is why Wikia moved all their wikis to subdomains: in order to piggyback on the pagerank of the main site.
As a result there are a ton of long-dead wikis on Wikia that still get more search traffic than the active equivalent. Obviously this hurts users, since they get long-outdated information as a result.
In short, once a wiki is placed on Wikia, it's basically impossible to ever move it anywhere else because of Google's anti-duplicate biasing.
See http://en.wikipedia.org/wiki/Wikia#Controversy for more info.