Dive Brief: 

• Big name brands including American Express, GE Capital, Farmers, Staples and Samsung all made Mdotlabs' list of companies being scammed by bot traffic.
• To discover the false traffic, Mdotlabs set up a "sting" with 15 fake websites. The firm reached out to traffic vendors to send phony traffic to the sites, identified shady tags that ran invisible pop-ups and then searched the Web for the same tags on legitimate websites. 
• Mdotlabs estimates a total of approximately 15 billion phony ad impressions per month in the U.S., and the damages are likely $200 million a year. 

Dive Insight: 

During its "sting" operation, Mdotlabs found vendors who sold on a "pay-per-view basis." The tags used by the vendors caused a high number of invisible pop-unders to appear, all of which were never seen by the user but contributed to false traffic data. Mdotlabs offers protections against fraudulent traffic, so their "sting" is a marketing move in and of itself, but any information brands can get about how bot scams work is a plus.