Hmm, maybe its just because I'm a relative newbie (especially online) but I can't really ever see folding KK preflop without a massive read on the guy you are going against. I mean more times then not the second best possible hand is in fact the best hand. I just can't make this fold playing poker based on the number of people who play AK like AA or KK almost exactly. A lot of people also play QQ very similarly. Therefore villain's range is QQ-AA with AK and occassionally even JJ. With KK you don't just have most of his range beat, you've got it dominated. I'm always looking to get all in preflop with KK. In fact I would say KK is probably my winningest hand because its far easier to get away from than AA if you don't get all in preflop.