Are holiday cards defunct?

We had a professional photographer come out to the house a few weeks back to shoot our little family photo (particularly momentous for the removal of my teenager’s braces!).  I went to upload the photos to one of those card-making sites when I paused.  And I thought:  most of the families on my holiday list are also my Facebook friends.  Why not just post the photos there?  I have never been one of those long annual family letter writers (though don’t get me wrong, I adore getting them from those brave souls who do venture to write them!)  Is it worthwhile to just send a photo of my little family with some holiday/New Year greetings?  Is it a waste of time and money (and environmentally unsound?)  Or is it a welcome tradition that people would miss if I didn’t do it?  Editor’s note:  we did not send cards last year because we’d just had our daughter’ bat mitzvah and had been in touch with all the important people already.  So do I break the chain and just not bother?  Do people still like getting them?