Why is Maple so popular?

I think the addiction is also fueled by the fact that there is no reason NOT to play if you've got free time. Unlike games like WoW and stuff where you need to buy playtime, you can just fire maple up at any point, even if it's just for 5 minutes.

This is definitely one of the biggest factors. As ridiculous as Nexon's "I can because it's free" slogan was, it isn't far from the truth.

Another factor is friends. If my longtime buddies stopped playing, I probably would quit as well.