View Post Ad Biz | Agencies | What The?? And Now, a 2013 Recap Courtesy of Seiden’s Holiday Card By Erik Oster on Dec. 17, 2013 - 1:26 PM The holiday card for New York agency Seiden features the Harlem Shake, an old lady reading Fifty Shades of Grey, and just about every trend of 2013 that they could fit in 2:39. Their card begins with a setup of Matt Seiden himself ...