Both the NY Times and Washington Post carried stories about an FTC study on the amount of money spent on food advertising directed towards children and teens. (Also see the Ethicurean article.) Both reported the figure: $1.6 billion in 2006. Both buried deeply in the story the fact that critics of the food industry had been using the figure of $10 billion (or higher) in their attacks on the industry.
Classifying such advertising has got to be difficult--mostly in the eye of the beholder, I would think. And what costs to include or exclude is also judgmental. (One expert suggested that excluding travel and promotion expenses accounted for some of the difference; that's a lot of first class airline seats.) So there is no true figure.
But still, estimates that vary not by 50 percent but by 500 percent? Give me a break. Perhaps the lede (I love the word and I think it's the first time I've ever used it) should have been more focused on the discrepancy in figures, and what it might imply for consumers of stories--take all estimates with more than your recommended daily allowance of salt.