Facebook has pivoted its ad server Atlas (which it bought for hundreds of millions from Microsoft in 2013) to be used as a measurement tool, a development which emerged amid much controversy for the social network. In the first of a two-part series, The Drum probed some of the industry’s largest media spenders to gauge their reaction.

Facebook’s meteoric propulsion to the very top tier of the media landscape has been fuelled by its reach, frequency of usage by over a billion people, and more crucially the richness of its audience data.

Read the full Drum article here.