Online advertisers in the USA spent a record $10 billion (€7.5bn, £5.24bn) last year.
The figures, released by the Interactive Advertising Bureau and accountants PricewaterhouseCoopers, show the internet attracted 32% more adspend than in 2003, a growth rate outpacing by far the overall US ad market, which rose by 5.6%.
The numbers are the strongest since the dotcom boom of 2000. In value terms online advertisers spent more than American moviegoers while the internet is predicted to overtake magazine advertising within two years.
Data sourced from MediaGuardian.co.uk; additional content by WARC staff