It's a way to keep track of people...for example if you click on your profile you'll see it says 'person marked by X people'. That's how many people have clicked to be able to sort of keep your name in a name list of sorts. Now that I think about it, BillyJack is the king of person marks LOL, my own personal person mark hero, you can ask him if my answer doesn't make sense.
~Mel Be the person who does what others talk about doing!