The existential threat of Google and Facebook are causing competitors to ally in France. Major French national newspaper and magazine groups are setting aside traditional rivalries to scale their digital advertising offers to rival the duopoly, while also ridding their digital ad supply chains of unnecessary intermediaries.

Le Monde and Le Figaro, traditionally fierce newspaper rivals, are letting advertisers book digital ad campaigns across their combined portfolio, using the same display or video ad formats for the first time. At the same time, Lagardère, Prisma Media, Condé Nast, Le Parisien and broadcaster M6 are pooling audience data in an initiative involving around 15 publishers.

Both Le Monde and Le Figaro have stressed that combining forces in this way is a necessary step if they’re to compete with the likes of Facebook and Google for advertising spend. Their alliance, called “Skyline,” is an intentional show of strength to the advertising market. Together, these media groups generated 35 million unique users in May, according to Médiamétrie. From September, advertisers will have the option to run campaigns across all the sites of the 20 media brands they have between them, which include HuffPost.fr, a media partner of Le Monde’s in France. In France, that puts them behind Google, which has 44 million visitors, Facebook (40 million) and Microsoft (36 million).

Advertisers will be able to check their campaign via auditor Integral Ad Science, which is already a partner of both media groups. “The Skyline project is all about giving the message to the market that these media forces are bigger and stronger — that they want to combine forces and regain strength with advertisers,” said Etienne Watrigant, executive lead for publishers at Integral Ad Science in France.

Meanwhile, the separate audience-data pooling alliance with 15 publishers, called “Gravity,” reaches 44 percent of the French population every day, a figure that will rise to 50 percent by the fall, according to alliance member Les Echos. Google reportedly has a market reach of 60 percent, and Facebook has 70 percent in France, although eMarketer puts Facebook’s reach at around the 40 percent mark there.

Publisher alliances have a checkered history. Le Monde and Le Figaro chiefs defended the timing of the launch in their press briefing to French media, saying that previously joining forces would have been blocked by the Competition Authority, but the rise of tech companies like Google, Amazon, Facebook and Apple have changed the stakes.

The time is also ripe for traditional media groups to capitalize on some of the challenges the platforms are facing regarding brand safety (YouTube) and low viewability (Facebook). “They want to show French agencies and advertisers that they perform well when it comes to brand safety and viewability,” said Clément Bascoulergue, France sales director for Integral Ad Science. “Walled gardens are facing new challenges. Also, publishers have a new challenge to deal with next year with the new policies around cookies coming into force in Europe, so now is a good time to make this play.”

Although the premise of each alliance is similar (to have the scale and data play to compete with the duopoly), there are big differences in each approach. The Gravity alliance is a data-pooling initiative, an approach Le Monde and and Le Figaro don’t favor.

“Switching the data of my internet users to a kind of pot that would market them without my having mastered it is a mistake,” said Louis Dreyfus, managing director of Le Monde Group, in a press briefing to French media.

Skyline’s advertiser customers will be able to target users of the sites of both groups according to their profiles, purchase intentions and locations, as well as by categories like news or lifestyle. Both media houses will continue to sell their own inventory, too, and 50 people from across each company will be dedicated to Skyline.

The French media market is highly fragmented, meaning that advertisers typically deal with Google and Facebook, then dozens of separate publishers. Other programmatic ad alliances exist in France, like La Place and Audience Square — both of which are in talks over a potential merger. But La Place has contained more midsize publishers, not media juggernauts like Le Monde, Le Figaro or Lagardère. Gravity is more akin in model to the ongoing (and first) publisher programmatic marketplace in France.