Its all about emptiying your hand and going all out and hoping you are quicker then the opponent can react.
Sometimes i lose to zoolocks in turn 4-5 and they just have a full board and an empty hand. I have such a deck too for dailies (copied from the inernet) and it works just great. But honestly...its boring as fuck. If all my decks would be so exciting i would quit HS in 2 days.
One reason is for sure the high success rate and a relative cheap deck. But honestly, when i win i get no satisfaction or motivation from the win cause i feel like my skill contribution to it was like 0.
(I wrote this post after i got win 5 games with lock and i won them and not after some bad loss)