[Winston Smith]

This may not be at all relevant but according to the ICO website the Privacy and Electronic Communications Regulations seem to be fairly strict about direct marketing. Surely this would fall under that, as I understand the way Phorms system works its using targetted adverts based on your own browsing history. I admit I havent read the detailed guidance (IANAL and legalese doesnt half seem to be complex for the sake of being complex). To quote a part of their guidance:

Marketers cannot send, or instigate the sending of, unsolicited marketing material by electronic mail to an individual subscriber unless the subscriber has previously notified them that they consent, for the time being, to receiving such communications. There is an exception to this rule which has been widely referred to as the ‘soft opt-in‘ (Regulation 22(2) refers).

&

Oops - missed the last sentence:
It all seems to refer to opt-in - in that you have to give your consent.

I know it all refers to email but is it at all similar?

WinstonS