Facebook is shutting down Audience Network, its platform for advertisers to extend Facebook campaigns on third-party apps, on mobile websites.
The move, which begins on 11 April, will come as a setback for online publishers that benefit from the ad revenue shared between them and Facebook. It does not affect apps, which are used by the likes of TikTok, Activision and Tinder.
The social media giant announced that it had made the decision "based on where we see growing demand from our partners, which is in other formats across mobile apps".
This demand is likely to be fuelled by Google’s announcement last month that third-party cookies will no longer be available to online advertisers within its Chrome browser. Apple and Mozilla have already banned third-party cookies from its respective Safari and Firefox browsers.
Moreover, the UK’s Information Commissioner's Office is investigating the real-time bidding industry, a key market for how online ads are traded programmatically.
Facebook launched Audience Network in 2014 and extended the platform to include mobile websites two years later. It uses Facebook data to sell ads on apps and websites outside the social network and paid more than $1.5bn (£1.2bn) to publishers and developers in 2018.
While Facebook does not break this figure down into mobile versus app, research by eMarketer estimated that mobile web adspend is generally much smaller than in-app mobile spend ($17.4bn versus $81.7bn in the US last year, for example).