CNBC, perhaps wiser to today's launch of Fox Business Channel than News Corp. itself, arranged a while back to snag exclusive online ad deals with the Dow Jones-owned MarketWatch.com and WSJ.com.

Except those two websites are now owned by Rupert Murdoch's News Corp., of course. And, suddenly savvy to the irony and ego slug of having CNBC ads blanket the homepage of MarketWatch.com, Dow Jones ad reps informed CNBC that, unfortunately, their ads would not be appearing.

No official reason was given, reports the Times, except that Dow Jones "retain[s] the right to adjust the precise placement and timing of online advertisements, including to accommodate links from other Web sites."

And it's not like Fox News has many flacks to spare these days.

CNBC's ad agency Spark Communications, meanwhile, argues that it had a signed contract in place.

So what gives?

Avoiding public embarrassment, that's what. But don't think News Corp.'s savvy extends too far. In booting CNBC's ads, it's not like they replaced 'em with a campaign to plug Fox Business Channel.