Pop Cap through a dealer known as Facebook.
Bejeweled set a standard for match-three games a long while ago with its rapid pace, colorful gems, and pick-up-and-play style. Blitz takes it a little further by limiting games to one minute matches. Just one minute! It's always frantic playing against an ever-dwindling clock, but limiting it so much really narrows down the "just one more game" scope.
And fighting to be above your Facebook friends on the leaderboard is a big plus too. Allow me to brag with my screenshot above of my best score (note that it was before boosts were introduced). Ego turning off now: 25,000 isn't that bad of a score ::shrug::
-- "I mean, sending me down here to play games! Who does he calculate he is?"