You guys surely noticed that you can no longer "act as your page"? If you'd like to comment as your page, you gotta switch user at the comment form, right? You no longer stay logged in as your page. It's been that way for a few months. So what did I realize? That before this change happened, I had "liked things as my page". I went to look and voilà : a certain page used to "like and follow" a bunch of unrelated pages. What did I notice? That a lot of my likes and reach were about a certain subject, even though my page is not related to that subject!!! I post something related to A, and get no reach. But then I post related to that specific subject and get 200 shares instantly.... WTF???? Then it downed on me : my former page likes were directing my posts to people who also like those pages. So I went and unliked every single thing the page used to like..... Bam. Instant reach boost across the board cuz my page is no longer tied to those audiences. A lot of people complain about losing organic reach since a few months ago. It may be related to this after all. Hope it helps.