I enjoyed your post so much. I also felt very identified with it. In an era where everything must to be fast and at the reach of a clicking button it is very pleasant to get a thank you card on paper (in certain cases if there is no other option via email.) I am one of the few that still use paper. If someone took the time to thank you through that way, I think it is because I am still important. Besides, nowadays, it is a very original form of approaching a business partner that will appreciate that personal and caring gesture.