Ask a Ninja is a sexy addition to John Battelle's ad network. The online video show, in which a balaclava-wearing geek gives absurd answers to readers' questions, is one of the few to show up on advertisers' radar screens. Comscore, the audience database much consulted by media buyers, gave the site 154,000 unique visitors last month. But Ask a Ninja's choice of FM Publishing as advertising reps comes at a price. According to one report, Battelle's network guaranteed $300,000 to win the client. Which gives rise to two interesting questions. How will FM handle other sites, disappointed in its representation, which want equal treatment? And is this the first sign of a bidding war, for popular sites at least, by ad networks?