Michael Gray has already schooled you once, and this is largely a re-hash of that idea, with an update for your ninjopoly fun.
Ninjopoly - Make Sure Your Campaign Itself is Compelling
I just stopped by the old Ask a Ninja about Net Neutrality and at the end there is a "Sponsored by ask.com - go search ask.com about ninjopoly" and if you do that...you get nothing. A whole bucket of nothing. So, you paid to get that word added to his movie, and then people search on it, and the find the ask a ninja page and a keyword stuffed page. Yay. That's not going to get those new visitors to come back. If you had something awesome there I might become an ask.com user, but as it is, it turned me off so hard I'm ranting about it! Hardly the goal of your campaign, right?
Ninjopoly - Make Sure Search Campaigns Can't be Gamed
There have been a few marketing campaigns recently that instructed users to, for example, "google for pontiac" and now "search ask.com for ninjopoly". These campaigns can be great, people love a a surprising result for a search. Do not enter into this strategy lightly! There are search engine optimizers out there who will piggy back on your campaign or use PPC to get their advertising at the top of the page if you don't already own that spot. Be prepared for that situation by cementing your control of the SERP and PPC prior to launching your campaign. Especially for a word like ninjopoly that is completely made up it is totally simple to control the SERPS if you have advanced knowledge of the campaign...
Ask a Ninja's defnition of Ninjopoly
From the video page
a very long and boring game.
it's played on a completely black board with invisible game pieces.
and you just throw a smoke bomb and randomly move your game piece around.
it ends when one player kills another player.
just like regular monopoly.
this one's not so good for the family.
Ninjopoly: from kilton badley.
For posterity - here is the SERP from ask.com when I first wrote this