Uh oh! Scary times for Facebook. Deviating from your core product / service has brought many of a business crumbling down. Let's see what happens with this.
It's also necessary if you want to build a huge business.
Apple made computers. They went into mp3 players, that made them.
Google did search. They now do, well, everything.
There comes a point where to keep growing you have to push into new sectors and do new things. This is an investment in the future. Facebook is doing everything it can to maintain its position. Snapchat offer, Whatsapp, virtual reality.. All things which could potentially disrupt the way Facebook is used worldwide.
The important thing is to make sure you give the team autonomy to do the new things well. Make sure you have experts in that sector running that part of the business. Most huge corporate businesses fail when that original entrepreneurial drive is lost, and innovation stops. They then squeeze all the profit they can out of existing products until they are usurped by innovators who destroy their business.
Case in point -- Kodak.