The Guardian’s Facebook app has been downloaded eight million times since it was launched six months ago, seeing around 40,000 downloads a day.

Speaking at the Guardian Changing Media Summit, Tanya Cordrey, director of digital development at Guardian News and Media, said the news outlet has been “blown away by the results”.

The “frictionless sharing” app works by readers opting in to share all articles they read with their Facebook friends, generating more traffic for the news site with “no editorial curation”.

She later explained that the Guardian has generated more money through ad revenue from the app than the news organisation spent on building it.

Six months ago Google provided 40 per cent of the Guardian’s traffic. The launch of the Facebook app resulted in a “seismic shift” with social exceeding search as a driver on several occasions in February (see above photograph).

Cordrey predicted:

It’s only a matter of time until social overtakes search for the Guardian.

She said that the audience becomes more global everyday, providing “an amazing opportunity to learn about this new audience”.

It’s the audience we want to learn about rather than the platform [Facebook]

Readers are in “habitual grazing mode”, Cordrey said, traffic peaking in “the middle of the afternoon”.

Addressing those who believe the app has implications for privacy, Cordrey said “we are acutely aware of the critics” but readers are not being driven away or removing content they have read from their Facebook timeline.

“Once people have it, they use it,” Cordrey said, explaining “only a tiny percentage of people” have taken up the option of hiding their reading habits.

Earlier in the day Karla Geci, strategic partner development for Facebook said that it would be “just weird and awkward to read a whole article inside of Facebook”, saying Facebook’s role is enabling “distribution and discovery” rather than taking traffic away from publishers.

Asking herself if frictionless sharing “is creepy”, Geci said:

People are quite interested in being an influencer in their circles. Sharing what you are reading is something you did any way.