Adwords conversion tracking code.
https://support.google.com/adwords/answer/6095821#get_tag
Analytics and Tracking · Advertiser Tracking
Get access to data on 1,696,481 websites that are Google AdWords Conversion Customers. We know of 1,079,731 live websites using Google AdWords Conversion and an additional 616,750 sites that used Google AdWords Conversion historically and 549,893 websites in the United States.
Get a list of 1,696,481 websites using Google AdWords Conversion which includes location information, hosting data, contact details, 1,079,731 currently live websites and an additional 2,211,295 domains that redirect to sites in this list. 616,750 sites that used this technology previously and 549,893 websites in the United States currently using Google AdWords Conversion.