MarketWatch's tech diva Bambi Francisco left the Dow Jones & Co. (NYSE: DJ) Web site late Friday after questions were raised about her financial interest in Vator.TV, a web site that features video interviews with technology executives.

Stories in CNET and The Wall Street Journal pointed out that Francisco regularly wrote about companies that appeared on Vator.TV or had dealings with backer Peter Thiel, the co-founder of PayPal who is now a venture capitalist. Most news organizations forbid journalists from writing about companies in which they have a financial interest.

MarketWatch made an exception for Francisco, who is well-known in Silicon Valley. David Calloway, the editor-in-chief of the site, told CNET that he told Francisco to avoid writing about Vator.TV and the companies that use the service.

That agreement that was doomed to fail since Vator.TV interviewed tech executives and Francisco did the same thing for MarketWatch. Her bosses should have realized that arrangement wasn't working before other news agencies pointed that out to them.

Even though several hours before filing her final column, Francisco told the tech news service that she did nothing wrong, her departure was unavoidable. Advertisers won't pay top rates to advertise with news organizations whose credibility is in question.

Dow Jones deserves some credit for not sweeping this matter under the rug the way that CNBC did with the Maria Bartiromo episode.