The new feature is powered by mobile-photo-to-keepsake startup Sincerely and began as a hackathon project it allows you to mail a physical postcard to a friend. You can even add a message that will be sent to the friend with the card or send prints of their pictures.
The social network has today started permitting a small group of members to mail Facebook photos as printed postcards to their social network pals.
If you’re in the limited group trial, under the photo you are viewing you will see a “Mail Postcard” button. Clicking this opens a screen, seen above, that you can enter your message and the recipient’s address on. Click send and off the order goes to production and mailing. Simple, and likely effective.