Well, those are some interesting ideas, I must say that. Can't say though that "tagging" or world record breaking is the path I could walk. But advertising on GameReview sites would be my choice, because it is cheap, effective (in case of a good review ^^) and it attracts exactly the target audience I need. TV, for instance, is a lot more expensive, and the commercials are wasted on people that do not care about gaming at all.
Now, I got to find out, what kind of sites do secretaries visit! I know they all love to play casual games in the office!