Wikia is to be used for community editing, not just to put up links to another website. Non-official advertising is not permitted. See Wikia:Advertising on Wikia.
a Wikimedia project
Wikia, Inc. and Wikimedia are separate organizations.
Wikia is not Wikipedia and we aim to not duplicate Wikimedia projects. Although Wikia shares some of the goals of Wikipedia, the two are not "sister projects" since Wikia is not a Wikimedia project (as explained above)
a link farm
Wikis on Wikia should contain actual content, not just be a link repository pointing to other sites.