The decision comes amid growing calls to diversify TV measurement strategies.
TOP OF THE CHARTS: Asian markets unsurprisingly leading the way in mobile use, but it's getting bigger everywhere, according to ComScore's latest report, which also highlights Amazon's rapid global growth.
China is "not a corporate priority for Comscore at this stage".
Free self-service tool to measure how display, video and mobile ads are actually viewed.
Ahead of its full-year earnings call, Facebook has expanded its third-party verification partnerships to try and avert future metrics blunders.
Reckoner compares what Nielsen DAR and ComScore vCE can deliver to marketers.
Top news, insights and analysis every weekday
Sign up for Campaign Bulletins