1. Ad Words
https://adwords.google.com/home/
2. Double Click
https://www.doubleclickbygoogle.com/
3. comScore: Measure What Matters to Make Cross-Platform Audiences and Advertising More Valuable
https://www.comscore.com
4. Invalid Traffic
http://www.comscore.com/Products/Advertising-Analytics/Invalid-Traffic
5. Battling Bots: comScore’s Ongoing Efforts to Detect and Remove Non-Human Traffic
https://www.comscore.com/esl/Insights/Blog/Battling-Bots-comScores-Ongoing-Efforts-to-Detect-and-Remove-Non-Human-Traffic