People love postcards but only few dedicate time to them
On N=100 about 2/3 prefer or significantly prefer a hand written postcard or letter to the typical other interaction such as calls, WhatsApp (line of 0.1 for average) but only few dedicate time to it (% of total time spent interacting with friends in a month).
This could be a great opportunity to really write some Christmas cards for this season, handwritten, dedicated, and a real surprise once they show up on the doorstep.