Why Do People Post Messages To Their Deceased Relatives And Friends On Facebook?

Every day it’s something like “Happy Birthday In Heaven Great Grandpa Joe” or something to that effect as though Great Grandpa Joe is going to read or receive this message in the great beyond in spite of having never used Face book a day in his life. This is the successor to posting messages to deceased people in rag newspapers that the person certainly isn’t going to be reading if they are in a better/higher place.