The Kelsey Group predicts that the global market for local search, including online Yellow Pages, will grow at an annual rate of 30.5 percent in the next five years, reaching $13 billion in 2010 from the $3.4 billion in 2005, report MediaPost and ClickZ. Interactive classifieds are forecast to grow 7.9 percent per year, reaching $21.1 billion in 2010, from $14.4 billion in 2005. Kelsey also predicted very high annual growth for pay-per-call.

"I think that we're going to see pay-per-call in the newspapers. I think we'll see it as a way to retain advertisers," said Kelsey Group Analyst Greg Sterling. Pay-per-call is forecast to grow at a 130 percent annual rate, reaching $3.7 billion in 2010, from $57 million in 2005.

"We're going to see a trend towards more performance media, where value is proven and self-evident to the advertiser, and that's the influence of internet on traditional marketing," Sterling said.