About That Advertising Comeback…

After cratering for more than a year, the ad business is back. But it’s not back everywhere. And it’s probably not as strong as you think it is.

That’s the takeaway from a note by Barclays analyst Anthony DiClemente, who has knocked down his ad estimates for 2010. It’s the most modest of reductions–he’s now predicting five percent growth for U.S. ad spending, instead of 5.5 percent–but it’s a contrast to most other ad predictors, who have been revising their forecasts upward for some time.

If you spend most of your time watching Web publishers and TV networks, you might not see it: Everyone from Google (GOOG) to GE’s (GE) NBC Universal have been reporting very good growth numbers. So what gives?

Everything that isn’t on the Web or on your TV screen, DiClemente says. The radio, magazine and newspaper businesses have been reporting lousy results this year, and that’s enough to drag down the rest of the business (click images to enlarge):

We’ll get more info about the state of the ad market next week, when a swath of big media companies, including CBS (CBS), News Corp. (NWS), Time Warner (TWX) and AOL (AOL) turn in their Q2 report cards. But even if you assume that those guys report healthy-looking numbers, it’s important to remember that they are based on very weak comps from the previous year. Which means that industries that are still posting declines are really, really, down. DiClemente spells it out in this chart:

Useful, sobering numbers. We’ll refer back to them next week.