The credit crunch has not affected US internet advertising spend, new research reveals.

IDC reported that total revenue "surged" by 23.9 per cent to $7.1bn in the first quarter compared to $5.7bn in 1Q07.

The analyst firm expects web advertising to continue to "expand rapidly" during 2008, even though total advertising spending across all media is likely to be cut back.

IDC's report found that Google continued to extend its lead in the US internet advertising market in the first quarter. The company's estimated net US advertising market share was 24.8 per cent in 1Q08, up from 23.1 per cent in 1Q07.

"The current economic crisis puts pressure on advertisers to save money and find more effective marketing channels," said Karsten Weide, programme director for digital marketplace and new media at IDC.

"Effectively, the crisis accelerates the shift of advertising budgets from traditional media into new media."

IDC anticipates that the threat of a potential recession will decrease ad expenditure across all media by as much as seven per cent in 2008.

However, the analyst firm believes that quarterly online advertising growth will still increase at rates around the 15 to 20 per cent range in 2008.