Apart from the Children of the family, I stopped sending paper greetings cards years ago!
I send them Electronically, and feel that it's somewhat saving the environment, helping prevent bugs and viruses, especially from those who insist on licking the envelope glue to seal it up, and continue to do so even when they are ill, potentially sending their germs to infect again!
I also give an annual donation to a charity equivalent to the money saved by not sending cards, and even some of my Grandchildren now request that they prefare to get a Birthday greeting and maybe a bit of pocket money electronically rather than the actually thing!