How do these blogs build a user base given the proliferation of content curation channels like Pinterest (just save a "cupcake" search), Tumblr, and others? I r

How do these blogs build a user base given the proliferation of content curation channels like Pinterest (just save a "cupcake" search), Tumblr, and others? I recently went on cuteoverload which was huge at one point and there's barely any comment activity anymore.