Ad Age surveyed seven firms tracking fraud about the activity they're seeing.
What is the most prominent type of ad fraud?
Bots account for 90% of all fraud, says Integral. According to DoubleVerify, 30% of all programmatic buys could be fraudulent.
What is the most costly type of ad fraud?
Forensiq, Integral and Vindico agree that bots are the most costly. But Telemetry, White Ops and ComScore say it's video fraud.
What is the hardest type of ad fraud to get rid of?
Again, Integral and Vindico say bots, but Telemetry claims vendor tricks, such as mixing suboptimal traffic into a legitimate campaign are the hardest.
Can you put a dollar figure on the amount of fraudulent ads you've witnessed?
$120 million in 2014, according to Vindico, though DoubleVerify puts the figure at more than $1 million per day.
What portion of total digital ad spend is fraudulent?
Forensiq and Integral place the figure at 10% to 15%. WhiteOps' 2015 estimate is $6.3 billion.