Online advertising in the UK is expected to break the £1 billion ($1.75bn; €1.47bn) barrier by the end of this year.
The Internet Advertising Bureau says UK advertisers spent a record £490 million online between January and June this year, a rise of 62% on the same period last year and more than the whole of 2003.
The IAB's figures, produced by PricewaterhouseCoopers, indicate that the internet took a 5.5% share of the advertising market in the first half of 2005, compared with 3.9% for the whole of 2004, thereby overtaking outdoor advertising's 5.1% slice of the cake.
IAB ceo Guy Phillipson says faster connection speeds through broadband are a key factor in the medium's success. Says he: "Broadband homes spend nearly twice as long online as those with dialup connections, and where consumers go, advertisers are following."
The Interactive Media in Retail Group forecasts a boom in online shopping through the upcoming holiday season and predicts internet sales will reach a total of £19.6bn for 2005.
Data sourced from MediaGuardian.co.uk; additional content by WARC staff