Three ISPs BT (NYSE: BT), TalkTalk and Virgin Media—representing 70 percent of the British ISP market--have signed on to join advertising technology company Phorm’s new ad platform that will give them a cut of more targeted online ad sales. The platform, the Open Internet Exchange (OIX) is based on an internet surfer’s anonymous browsing activity, which the company claims ensures that consumers receive fewer irrelevant ads.

Unlike traditional web ad services, OIX is embedded into the back end of the ISP, which means the platform can track a consumer’s web surfing across all web sites. It uses anonymised ISP data streams to create customer advertising “channels,” or groupings of surfers who demonstrate interest in specific products and service categories and then uses this information to serve relevant ads based on a user’s browsing activity. The user and their internet IP address remain anonymous.  Advertisers are ensured their messages are more targeted, while web sites can charge more as the ads presumably deliver better click through rates. ISPs get a cut as the platform is integrated into their own technology.

Phorm has already signed on Ft.Com and iVillage, among other web sites, as well as ad agency Universal McCann. The company hopes to sign on more ISPs in the future (release).  In the US, a similar start up NebuAd received $30 million in funding.

In other online advertising news, NMA reports that a majority of its publisher sites have pulled out of the Orange Ad Network. The network is said to be working a new strategy after Allapprovedcars, Sidestep and TV Guide quit the platform and signed on with rival sales houses. According to Neil Packham, sales director for Portfolio Europe, which owns Allpprovedcars, said the Orange Ad Network was limited in the number of advertisers it could represent, as it could not represent rival ISPs or network operators. Packham reported, “The revenue never got where Orange said it would.” Orange said it plans to trial and roll out new services that will offer more ad opportunities for clients.