Some data are better than no data, I suppose, but it always pays to be skeptical when companies disclose financial data selectively when touting the success of this or that venture. And that’s certainly true when it comes to digital publishing.

Forbes Media’s CEO Mike Perlis wrote a memo, reported by Ad Week’s Emma Bazilian, claiming strong performance from digital ads on forbes.com, particularly from its native ad program, known as BrandVoice. (The format has its own problems, of course, but leave that aside.) I’m sure all the following is true, but the data here are highly selective, so a grain of salt is required:

The company achieved its best financial performance in five years in 2012, according to a memo released this morning by Forbes Media CEO Mike Perlis. Digital ad revenue, which increased 19 percent year over year, accounted for half of the company’s total ad revenue for the year, said Perlis. Ten percent of total revenue came from advertisers who incorporated BrandVoice into their buys, and by the end of this year, that share is estimated to rise to 25 percent.

Digital ad growth of 19 percent is definitely good. But keep in mind, digital ad spending on U.S. magazines generally rose 15.5 percent in 2012 and is projected for a 12 percent rise this year, according to emarketer. (Newspapers, if you’re wondering, saw digital ad growth slow to one percent in the last quarter of 2012.)

Forbes, which doesn’t have a paywall on its news content, is doing well ad-wise, and that’s good, but the rest of the industry is doing only slightly less well.

But the real questions is, as always, compared to what? Digital ads everywhere in US magazines are rising from a low base, and, at about $3 billion nationally, are still a fifth that of print ad sales. That digital ads now account for half of total ads at Forbes can be good news but can also be a function of shrinking print ad sales.

And while data from the Magazine Publishers Association show that total ad revenue indeed fell about 18 percent at Forbes since 2008, the magazine is still said to have posted $275 million in print-only ads sales in 2012. Following Perlis’s comments—that digital ad revenue “accounted for half of the company’s total ad revenue” for the year—that would mean digital ad revenue would be roughly the same, $275 million. That, ladies and gentlemen, is a huge number. The big caveat is that MPA don’t take into account discounting, which this estimate puts as high as 57 percent. Taking the most conservative number, the biggest discount, that puts print and digital ad sales at $156 million a piece. That’s STILL a big number.

By comparison, The New York Times’s site, which gets more than twice the traffic of Forbes’s, pulls in “only” around $180 million in digital ads, according to Ryan Chittum’s calculations.

A Forbes Media spokeswoman declined to comment on the company’s finances.

Forbes Media is closely held, so is free to disclose what it wants, and, to be fair, Perlis’s comments were meant for internal consumption. But the point is, out-of-context numbers will only take you so far. Remember when the Times’s David Carr reported that John Paton of the Journal Register Company, “among other feats…increased digital revenue by over 200 percent”?

We do.

The Financial Times, by contrast, is part of a public company, Pearson PLC, and offers a bit more visibility, but even that is limited.

The FT has become the Justin Bieber of the paywall set; I’ve been mighty impressed myself at how its digital subscription system has added materially to revenue when the naysayers kept saying paywalls wouldn’t work.

Dean Starkman Dean Starkman runs The Audit, CJR's business section, and is the author of The Watchdog That Didn't Bark: The Financial Crisis and the Disappearance of Investigative Journalism (Columbia University Press, January 2014).

Follow Dean on Twitter: @deanstarkman.