Phorm is considering paying users to encourage them to take part in its behavioural advertising system.

Last night, at its second townhall-style meeting, Kent Ertugrul the company's chief executive, said Phorm might try subsidising broadband or offer funds to charities to encourage surfers to choose to use Phorm.

Phorm is a behavioral advertising system which uses deep-packet inspection technology to decide which adverts to surface to surfers. Most display ads are based on the content of the page.

While the Guardian cancelled plans to work with Phorm, Virgin and Talk Talk have also signed onto the scheme, but only BT has run a trial, which ended in December. Aside from BT, Ertugrul said Phorm was also in talks with many other large internet service providers (ISPs). Ertugrul would not discuss the results of the BT trial, or say how many people chose to opt out of the system, which is called WebWise.

Paying users could be one way to ensure enough people choose to use the system, if targeted advertising isn't enough to draw them in.

One controversy surrounding the Phorm system is whether people will be required to opt out of it by their ISPs, or if it will use an opt in model. But Ertugrul said such decisions were up to ISPs and not even that important, so long as consumers are clearly told about the choice they were making.