#Wikimedia Foundation we use open standards, free software and for what it is worth we do reach out to people using social media including Facebook. However, if you mean business, you truly want to get me to do something, Facebook does not provide me with the tooling that I need.
When you send me a message, a mail from within Facebook, I have to go into Facebook to read your message and possibly to reply. I do not have that mail in my mail environment. As a consequence I can not readily find it.
Facebook created in its mail a walled garden. I can use Facebook when I want to post some information, an opinion whatever. It is useless to me when people use it to send me mail; I cannot manage the information it contains.