I think it depends on the couple. I find that there are too many couples out there that find the need to post everything that they are doing and posting pictures of every move they make. I'm a firm believer that on one needs to know all of my business because I feel that this can hurt a relationship. When people have the ability to see everything that goes on in your relationship you have no "secrets" (for lack of better words) that you can keep in a relationship. I find it fun to reminisce and say "Hey remember that time we...." but I feel that these moments will hold less value if the world already knows about them.
But at the same time, if this works for certain couples then who am I to say stop!
Thanks, now you have my mind racing!!!