I send postcards to a good friend of mine. I'll sit down and give a trip overview over 10 or so postcards. She enjoys seeing the sights on the cards and reading about my trip and I enjoy writing about it. One odd thing that I've noticed over the trips is one universal constant. Cards don't get there at the same time. On a recent trip to Ireland I sent all 10 cards at the same time in the same post box. They arrived over a 4 day span. Always wondered why...I mean a couple of days would be one thing....but 4?