US online advertising hit record levels in 2005, according to final figures released by the Internet Advertising Bureau.

The numbers, verified by PricewaterhouseCoopers, show internet adspend at $12.5 billion (€10.12bn; £7.01bn), up 30% on 2004. The figure represents 4.7% of total US adspend last year, up from around 3.7% in 2004.

The fourth quarter was strongest in terms of revenue, coming in at $3.6bn, an increase of 34% on the same period the previous year.

Search engine ads were the drivers of the boom, claiming 41% of advertising dollars, while spending on display advertising such as banners and sponsorships attracted 34% of budgets.

The report also reveals that 72% of 2005 ad dollars was allocated to the top ten web media companies - a figure unchanged from 2004.

Hypes IAB president/ceo Greg Stuart: "Interactive advertising continues to enjoy tremendous growth as marketers experience its overall effectiveness in building brands and delivering online and offline sales."

Data sourced from Adweek (USA); additional content by WARC staff