JupiterResearch forecasts that spending on online advertising - display and search - will grow at an average annual rate of 10 percent from 2005 to 2010 and will be driven by the automotive, media and entertainment, and financial services industries. The most impressive growth, according to the Jupiter report titled "U.S. Category Advertising Forecast, 2005 to 2010," is expected to come from automotive (yearly average of 24 percent) and travel (13 percent).

"Agencies and publishers must educate themselves on how industry categories prioritize online advertising and tailor their pitches to different industries," said Zia Wigder, VP and Research Director at JupiterResearch.

"Growing categories differ in the way they allocate funds to online advertising from their total spending," Wigder said. Today, telecom, media and entertainment, and finance are the leading categories online and make up nearly half of all online display and search advertising spending, according to Jupiter.

"Marketers are increasingly looking for the efficiencies of online campaigns that are integrated with their off-line campaigns," said David Schatsky, senior vice-president of research at JupiterResearch. "Agencies that can devise and manage integrated campaigns stand to gain more from rising ad budgets."