I sometimes ask because I'm bored or there's nothing really better to do. Or I ask because there's only me and the other person and no one else. for ex: "Mining level? :)" Then she/he answers, then asks, "you?" then i answer, then we comment on each other's levels and will eventually lead to debating, discussions and etc. It usually breaks the silence. But most of the time, I just ask out of curiosity, especially to the people I think is interesting. =)