From what I understand, this feature originally came from the acquisition of a startup called Karma. I wonder what the acqui-hired employees are going to do now.
http://techcrunch.com/2012/05/18/facebook-acquires-karma/
http://techcrunch.com/2012/09/27/facebook-gifts/
The latter article is very funny in retrospect.
The very use case I wanted for Facebook gifts were when I'm in California and want to send gifts to friends back in Canada (and vice versa).
Sure, maybe the gifts are cheesy (coffee mugs, etc) and limited, but I have always found that a real physical product in someone's hands has more impact than an impersonal gift card. I'm sad to see this service go, but I hope someone steps into this niche.