SAN JOSE, California: A media company that listens-in to internet-carried telephone conversations is hoping to target ads based on those chats - but the service has, understandably, raised privacy concerns.

Start-up firm Pudding Media is eavesdropping on calls to display ads on screen, in a similar way to search giant Google's scanning of emails to deliver ads relevant to messages received.

Users of the phone system get calls free in return for consenting to monitoring of their conversations and the information used for immediate marketing.

Pudding Media ceo Ariel Maislos claims the company has carefully considered privacy issues and is not keeping recordings or logs of the content of calls. In addition, ads only relate to current calls and will only arrive during the call itself.

He says: "The tradeoff of getting personalized content versus privacy is a concept that is accepted in the world."

However, Jonathan Sackett, chief digital officer for Arnold Worldwide, cautions: "We really have to look at the situation, because we're getting more intrusive with each passing technology."

Pudding Media is also exploring the service's potential for cellphones where carriers allow customers free calls in exchange for watching contextually relevant ads on their screens.

Data sourced from New York Times; additional content by WARC staff