We have seen it before:
Socialbakers relies on the count of total fans in a given day to be able to benchmark different pages. There is however a hidden factor, Facebook’s edge rank algorithm. The overall organic reach is not equal for every piece of content published and over the course of a month it is very likely that the page will only reach a portion of its total number of “fans”. (“Subscribers” is more like it.)
Since Socialbakers can’t access the organic, paid and viral reach of a post it relies on the little public information it has about all pages, number of fans.
And yet, this is the only way we have to benchmark a page against its competitors: not taking into account the investment in facebook sponsored posts and ads or the impact that a particular piece of content might have in regards to the exposure of a content published by brands.