I got into playing WoW through friends I knew from the local pub. They talked me into it one Christmas when I was on gardening leave and bored to tears. As I've played, I've made many good friends, strengthened my bonds with my real-life friends, and even met someone special. My WoW friends have helped me through some difficult times. It's a great form of escapism, and there's almost always somebody online to chat with about reforging, or cats, or complaining about PuGs, or nothing in particular.
How about you? Do you have real-life friends you met through WoW? Do your real-life friends play too? How does your social circle spill over between the world and Azeroth?