Facebook has announced changes to the social network’s ad serving method, closing its publisher-facing ad-tech unit LiveRail.

LiveRail, which primarily focused on automating the sale of in-app mobile video and native display ads, also enabled publishers to choose which video ads to serve on their desktop sites.

The division, which Facebook acquired in 2014, is set to shut down its ad server business and stop accepting new customers.

LiveRail was acquired in order to allow Facebook to compete with Google and AOL in the automated video ad sales market. However, it is now set to focus its attention on a newly launched, mobile focused Facebook Audience Network (FAN) service to rival Google AdSense in targeting users with Facebook insights.

“At Facebook, when there is a product that gains traction like Audience Network, we look for ways to build it out quickly and make it even better,” the Facebook blog stated. “That also means shifting away from other efforts, if necessary.”

In another blog entry, Facebook said that “just like the flip phone is disappearing, old communication styles are disappearing too”. This has led to speculation that the social media giant believes that phone numbers will soon be obsolete, despite several apps using them for security, authentication and activation.

This announcement comes shortly after Messenger was made accessible without a Facebook account.