Also,If you want to know why I added you it's because either:

1) You have the same interests as me, video game related or not.
2) Your profile icon, summary, and/or personality catches my interest in you, and you seem like a good person to be friends with.
3) You are friends with one of my friends, so you catch my attention.
4) I've seen you somewhere before and I find whatever it is you do interesting