Meh. Not a fan of celebrity culture. But is there much of a difference between a picture of you with someone famous and a picture of you on holidays enjoying yourself or with family? The premise being to have a memento of that time you enjoyed yourself, or more cynically as something to flaunt your enjoyment to others.

Could use a similar argument for the autographs or again, cynically as an easy way to increase value of objects. Market dictates objects' worth.