It may be the Internet age, yet consumers should expect old-fashioned junk mail to keep clogging their mailboxes.

Marketers' spending on direct mail will swell 7.5% to $64 billion next year after growing 8.5% this year, according to respected ad forecaster Robert Coen, who on Monday presented his industry-wide 2007 look-ahead at the annual media conference hosted by UBS. That means direct mail will continue to be one of the fastest-growing ad formats.

"More and more mail advertising is being used and all of this despite the fact that postal rates went up about 5%," says Coen, forecasting director at media buying agency Universal McCann.

Part of its allure, he says, is that it's easy for marketers to track response rates compared with, for example, a 30-second TV ad.

As for the ad spending outlook overall, both Coen and fellow ad forecaster Steve King, CEO of rival media-buying company ZenithOptimedia, say they expect U.S. spending growth to slow in 2007.

Coen sees total ad spending next year rising 4.8% to $298.8 billion.

King forecasts 4.2% growth and a total of $280.2 billion.

He says one trend will be that marketers will keep seeking ways to take advantage of the digital ad forms.

"A lot of the changes in our forecast are connected to technology," King says.

Among category forecasts:

• Broadcast TV, newspapers. Both see smaller 2007 spending increases than these businesses saw this year, but noted that Winter Olympics and the midterm elections pumped up 2006 spending.
• Internet. King predicts that ad spending on the Web will reach $16 billion this year, a 25% rise over 2005. Money spent on video ads will help push that up 29% to $18 billion in 2007.
• CBS' Chief Research Officer David Poltrack, who spoke after the advertising forecast panel, says he also sees strong ad potential in streaming network programming. "Broadband Internet distribution opens up a significant new advertising market for networks."
• Product placement on TV. As adoption of ad-skipping DVRs swells, product placement in shows will become increasingly valuable for marketers, says King. Poltrack reiterated his belief that more DVR use will let people watch even more TV. Thus, top broadcast shows "will become more valuable for product placement," he says.
• Outdoor. Digital enhancements to advertising, such as quick billboard changes, will drive spending growth 6% a year through 2009, predicts ZenithOptimedia.

"They allow instant, tailored (billboard content). Advertisers that have not traditionally been big billboard spenders are beginning to warm up to the medium," the company said in its forecast report.