If you’re settling in right now for a long holiday weekend, chances are you’re probably also catching up on errands, checking a few things off your to-do list or sorting through the unopened mail that tends to accumulate at this time of the year. Check that stack, though – are there fewer holiday cards in it than there were last year? Any holiday cards at all?

If the glitter-and-Santa card garland on your mantel (anyone else do this?) is looking a little uninspiring this year, blame social media – at least according to a Mintel International study quoted recently in the Chicago Tribune. According to the numbers, holiday card purchases have been slowing every year since 2005 and, in 2009, took the first decline ever. It’s just a .4% drop, but correlates directly to our rise in use of email and, more immediately, social networking such as Facebook. Says Kit Yarrow, Golden Gate University professor and researcher in Gen Y culture: “Gen Yers are notorious for not sending thank you notes and not RSVPing. I just think that method of communication is foreign to them.”

(Oh, and an aside: That Tribune article? All those mentions of greeting cards in the copy triggered a flood of banner ads for Hallmark. Contextual advertising works!)

For those who sent out a Facebook message this year instead of taking the time to address a stack of mail, history suggests you’re not alone. Ironically, the Tribune story points out, greeting cards themselves started out as another time- and face-saving measure during the holidays. Hallmark maintains that sending holiday cards originated in 1843 when a British businessman hired an artist to create a trinket he could send out in lieu of a more involved greeting. Fast-forward a century and a half and – even after the drop in popularity – Americans are expected to send out some 1.5 billion holiday cards this year, compared to Facebook’s 500 million members … and that’s Facebook on a global level, not just Stateside.

So, how many cards did you get in the mail this festive season? My personal count: four, and that’s living just a few miles away from the Hallmark plant. That said, the holiday greetings I’ve received via Facebook, Twitter or even email don’t amount to many more. Evidence of that Gen Y abandonment of the polite gesture, or what? (And does “Happy Xmas fwendies LOLOLOL” – from a Facebook friend who shall remain nameless – count as a holiday greeting at all, social media or no?)

For what it’s worth – and whether or not a blog post counts as a “real” holiday greeting – here’s wishing y’all a “merry merry.” Enjoy the holiday weekend, and whether you connect on paper, in person or on the Web, may you share it with the folks who mean the most.