• by Joe Mandese  @mp_joemandese, April 7, 2010

Online ad spending continues to be the bright spot, and the main source of traction in what appears to be an improving global advertising marketplace, according to the most recent in a quarterly series of ongoing tracking studies released this morning from Publicis' ZenithOptimedia Group.

"The rise of the Internet continued uninterrupted during the downturn - in fact, the downturn probably accelerated the shift of budgets from traditional media by focusing advertisers' minds on the importance of measurable return on investment," the agency's reported noted, estimating that the Internet's share of the overall advertising marketplace will jump to 13.9% this year, making it the third largest medium worldwide behind TV's 40.6% share, and newspaper's 21.7% share.

ZenithOptimedia predicts online media will begin to approach the No. 2 position by 2012 when it is projected to have a 17.1% share of global ad spending, vs. 19.4% for newspapers.

Paid search continues to be the "main engine" of online ad spending growth, according to the report, accounting for 50.2% of all online ad expenditures in 2009.

"We forecast this proportion to rise to 52.1% in 2012," the reports said, adding that online display advertising's contribution to total Internet spend fell from 33.0% in 2008 to 32.0% in 2009.

"We expect it to fall again to 31.7% in 2010," ZenithOptimedia predicted, adding, however, that "new formats - especially internet video - should help it grow faster than Internet advertising as a whole in 2011 and 2012, contributing 32.2% of internet ad expenditure by the latter year."

That improvement reflects an upgrade in the outlook for the overall advertising marketplace. ZenithOptimedia now expects worldwide ad spending to rise 4.1% in 2011, about double the rate of 2010's projected 2.2% rate of growth.

"Confidence in the global economic recovery, while tentative, continues to grow, and this improvement has been apparent in ad markets across the world," the agency said, adding, "Ad expenditure is accelerating in bullish developing markets, while in the developed world the downturn is coming to an end more quickly than expected."