If you have a Facebook email address, but you don't really use it - you're probably not alone. If you never even knew you had a Facebook email address - you're still probably not alone. Facebook rolled out their @facebook email addresses back in 2010 in an attempt to consolidate email with all types of messages - including Facebook messages. The problem for Facebook is that using Facebook as an email service hasn't been the most popular feature.
Now, in a pretty sly attempt to promote the Facebook email address, users are noticing that their contact info now features their firstname.lastname@example.org address as their primary email address.
I found this to be the case with my profile:
Unless you've customized your Facebook email address, it will consist of that vanity URL you made a while back, followed by @facebook.com (Facebook finally linked email and vanity URLs in April) If you never created the vanity URL, it will appear as a incredibly useful string of numbers.
Facebook email works by depositing any messages sent to it into your message inbox - the same one used for Facebook messages. Any message you send to an external email address (Gmail, Yahoo!, etc.) will show up in that person's inbox as coming from your @facebook email address.
Although fully functional, there are plenty of reasons why someone would want to shy away from using Facebook email as their default email. But even if you like using your Facebook email address, quietly changing your listed contact email to your Facebook email is a fairly questionable move from the company.
If you're upset, there is good news. Changing it back is a breeze.
Just edit your contact settings and choose "hidden from Timeline" for the Facebook email address and then choose which email address you want to change to "shown on Timeline."