Total US measured ad spend is projected to rise 4.2 percent in '08, with a gain of 3.6 percent in the first half of the year, followed by a 4.7 percent increase in the second half, according to the full-year forecast released Monday by TNS Media Intelligence, reports MarketingCharts.

Moreover, internet's share of ad spend is expected to surpass that of radio, TNS said (see "Share of Ad Spend by Medium," below).

"2008 is shaping up as a year of contrasts," said Jon Swallen, SVP Research of TNS Media Intelligence. "Aside from the continued double-digit growth rate of internet display advertising, spending gains will be driven predominately by the powerful combination of Summer Olympics and record-setting levels of political advertising."

However, a weakened economy will offset those gains "and have a dampening effect on the broader, core advertising market," he said.

YOY Growth by Medium

Internet display advertising is forecast to continue growing at double-digit rates in 2008 with Spot TV, Spanish Language Media, Outdoor and Cable Network TV also exceeding the overall market average.

Consumer Magazines and Network TV are projected to post small gains from 2007 levels, while Business-to-Business Magazines and Newspapers are expected to undergo outright declines in ad spending.

Share of Ad Spend by Medium

"The internet will continue to gain share, principally at the expense of newspapers," said Swallen.

"We track share of spending on a rolling two-year basis, in order to control for the biennial fluctuations associated with the Olympics and elections - events that disproportionately benefit television media. Our projections for the 2007-08 cycle indicate television and magazines will maintain their shares, while the internet will move past radio."