Facebook filters messages to keep you from getting spammed. This is mostly a very helpful tool, but occasionally real messages, business opportunities etc. get filtered because someone is in no way connected to you and trying to reach out.
Facebook just released a "dislike" button -- of sorts.
Mark Zuckerberg has staunchly rejected the notion that Facebook Home, the social network’s new Facebook-ified smartphone software, is a “phone.” In a sense, he’s right: Home isn’t a phone so much as it’s a three-by-five-inch messaging center designed to get the world hooked on chatting via Facebook.
Ever since Facebook revamped their Messages, there's been a filter placed on your inbox. The one that comes up automatically when you press the Messages icon is your "Inbox" where you get messages from your friends. But it turns out there's an "Other" inbox.