Online classifieds revenue is OK. But since it typically represents just a fraction of a fraction of existing print dollars … you'd rather base your growth on display ads. Especially, targeted, premium-priced ads that represent "new dollars" for the company.

That's the problem with yesterday's earnings reports from several newspaper companies. To be sure, online remains a bright spot in otherwise dour earnings. 3Q growth rates for online were 21.4 percent (New York Times Co.), 28 percent (Tribune) and 50 percent (Belo). And the growth is beginning to add up. Online revenues account for 7 percent of Belo's total earnings from newspapers, for instance.

But online classifieds are cheap. They don't really approximate the value of print ads. If they are inching up in share, it means that the high-value ads aren't selling very well.

Tribune, for instance, reported during its earnings call that "roughly 80 percent" of its online revenues now come from classifieds. If that number was closer to 50 percent, it would be much healthier. In print, classifieds account for roughly 34 percent of earnings, industrywide (albeit 50 percent of profits).

Largely, the growth of classifieds' share is due to the hearty rebound of real estate advertising and fairly neutral results from recruitment and auto. (yes, the real estate market is bad. That's why Realtors are advertising again).

Perhaps the number is not as significant as it seems. It isn't exactly clear what Tribune's "80 percent" covers. Does it, for instance, include X percent from CareerBuilder, Cars.com and other verticals? I couldn't tell. Moreover, display categories such as real estate feature ads are sometimes lumped in with listings. Still, it is a concern, and suggests that the replacement of print dollars with online dollars continues to be a tough road to hoe.

Right now, major newspapers are laying off or buying out hundreds of workers, citing, as Belo did, an "Internet-centric" marketplace. Meanwhile, some of the online divisions are hiring. One newspaper that I know, for instance, is trying to jumpstart its tiny online division by hiring 80 to 100 workers. We'll see whether the revenues it produces ultimately justify the faith in online growth. Whatever the amount, it can’t be made up of "80 percent classifieds."