Adwords conversion tracking code.
https://support.google.com/adwords/answer/6095821#get_tag
Analytics and Tracking · Advertiser Tracking
Get access to data on 2,867,964 websites that are Google AdWords Conversion Customers. We know of 1,932,967 live websites using Google AdWords Conversion and an additional 934,997 sites that used Google AdWords Conversion historically and 992,078 websites in the United States.
Get a list of 2,867,964 websites using Google AdWords Conversion which includes location information, hosting data, contact details, 1,932,967 currently live websites and an additional 3,047,480 domains that redirect to sites in this list. 934,997 sites that used this technology previously and 992,078 websites in the United States currently using Google AdWords Conversion.