Journalists use Signal to surface relevant trends, photos, videos and posts from Facebook and Instagram for use in their storytelling and reporting.
https://www.facebook.com/facebookmedia/get-started/signal
Analytics and Tracking
Get access to data on 5,500,799 websites that are Facebook Signal Customers. We know of 1,633,418 live websites using Facebook Signal and an additional 3,867,381 sites that used Facebook Signal historically and 896,604 websites in the United States.
Get a list of 5,500,799 websites using Facebook Signal which includes location information, hosting data, contact details, 1,633,418 currently live websites and an additional 2,964,983 domains that redirect to sites in this list. 3,867,381 sites that used this technology previously and 896,604 websites in the United States currently using Facebook Signal.