The current method of advertising on the internet could be under threat from a new piece of software which allows internet service providers to collect revenue from online advertisers rather than the websites consumers visit.
Most dot com operations get some or all of their revenue from online advertising, but currently, less than one per cent of ads are clicked on and advertisers are keen to improve their hit rate.
The software allows ads to be overlaid over those already on the website, meaning ISPs can target audiences with the kind of ads they are most likely to respond to.
Meltingpoint, the private company which owns the software, claims it puts the control of advertising in the hands of the broadcaster.
Chief executive Julian Graham-Rack said: "The ISP already has detailed information about customers and can, using the software, target advertising at them much more closely than a standard web page." He said he was hoping to sign up a number of ISPs soon.
But the software could open up a legal challenge, as website owners try to maintain control of their advertising. Some claim that their copyright will be infringed.
But Meltingpoint says it has taken legal advice and claims that, since the software covers a website but does not alter it, it does not infringe the page owners rights.