Since the possibility of printed photo’s, people would send memories to their loved ones. Photo postcards from foreign places to show the visit to those places; in the pre-Internet era, people would send a postcard to their loved ones on vacation to prove they were there and let them know that everything was ok. It is the time that telephone calls from abroad were hugely expensive. A postcard was cheap and easy to send.
But sending written letters and postcards has a romance about it. I sent a letter to a person, and a few days later it arrived. You never know when an answer would come and even if an answer would come. Sending a postcard from a foreign place feels like a surprise. You can still find postcards in tourist shops. But I am curious about how many postcards we send to loved ones nowadays.