VoIP operator Jajah has announced a partnership with advertising network Oridian Online Media Solutions to launch in-call advertising.

Jajah users will be able to opt-in to the programme from the end of November and earn money in their Jajah accounts while making phone calls.

The in-call advertising platform gives users the opportunity to earn credits, or potentially cover the entire cost of the call by listening to the adverts.

Earnings from an audio ad played while the call is being initiated are shared between the user and Jajah and credited to the user's account.

Many observers have seen in-call advertising as the inevitable next stage in Jajah's evolution, as it promises highly targeted, real-time promotional opportunities for advertisers.

A travel agent or airline could target an ad at users making a call from London to New York, for example, or a local restaurant could target users based on the area code.

Oridian reckons that sponsoring calls allows advertisers to establish new customer relationships and revenue streams, while telcos can generate greater average revenue per user by implementing the service alongside existing infrastructures.

"Ad networks are the bridge between advertisers and publishers and we are always on the lookout for new ways to bring dot.com publishers to international advertisers," said Jacob Nizri, chief executive at Oridian.

"Our partnership with Jajah is a significant development for our business, but more than that, it is revolutionary in terms of technology and the development of online advertising.

"By its very nature, Jajah creates permission-based, targeted audiences that Oridian can reach effectively, bringing new business to non-US advertisers and monetising US publishers' international traffic."

Trevor Healy, chief executive at Jajah, added: "To partner with the world's largest privately owned ad network is a huge win for Jajah and our partners.

"Oridian is an industry veteran with a global reach and a decade of experience that will prove invaluable as we enter into this new and exciting territory.

"We are now bringing the global power of Oridian to our mobile and fixed line operator partners so that they can monetise the massive inventory that exists in telephony today."