Over the past few years we've been hearing rumors every now and then about a possible Facebook phone. However, Mark Zuckerberg has just crushed that idea in Facebook's recent earnings call saying: “Building out a whole phone really wouldn’t make much sense for us to do.”
And indeed it doesn't. There are now close to 800 million Android and iOS devices in the market, and Android phones are now growing at a rate of 1 million per day, or 365+ million per year. Plus, there's a Facebook app for these devices, that does a pretty good job, or at least it should (if it's horrible, it's Facebook's own fault) at delivering the Facebook service to anyone using such a device.
So why would Facebook go into the hardware business, to build a phone around a single app? There's not that much more they could offer to users to warrant buying a “Facebook phone” instead of any other phone from another company that also has access to Facebook.
For some reason HTC got the crazy idea last year to make a “Facebook phone”, the HTC Cha Cha, which was basically just a regular Android phone, with a special hardware button for Facebook. But that's hardly a reason for anyone who uses Facebook to want to get that phone over other ones.
There are now rumors of HTC working with Facebook yet again for a new “Facebook phone”, which implies some kind of a successor to the HTC Cha Cha, rather than a phone made by Facebook. I doubt this new phone will be any more successful than the HTC Cha Cha, unless HTC makes it one of their flagship devices. But then, people would simply buy it because it would be such a great overall phone, rather than because it would be a “Facebook phone”.