Different people find different things attractive. Generally though the "treat em mean" approach works well at least in the initial phases of meeting someone. I believe it's because generally speaking it signifies that whilst you want the person, you don't need the person. That is an attractive quality to most people, I met a girl fairly recently who didn't like this approach and yet I found when I was actually nice to her and showed genuine interest we both ended up not wanting the relationship for different reasons which I found pretty ironic.

Generally though being a bit of a flirt I like to make some quips towards people that often seem a little mean to outsiders but yet within the target audience and myself it's quite funny. I find it weird however since there are 2 girls I work/worked with at the moment who I am fairly certain nothing would ever happen with and we spend our entire days making mean comments to each other and yet we get along really well. So I guess even in friendship, this can be true.