In the April 1st AdContrarian newsletter, Praneet Sharma of Method Media Intelligence points out the main reason that fraud estimates are widely inaccurate.
Recently CNBC reported $237B would be spent on digital advertising in 2018, and the Wall Street Journal reported 28% of internet traffic showed "non-human signals". Using these projections, $66B of advertising spend will be spent on fraud this calendar year.
Since fraudsters are one step ahead, it is reasonable to assume there is some undetected fraud. Praneet believes that "avoiding detection will be the major obstacle that fraudsters will present." Therefore, improved detection methods are critical to reducing the amount of wasted spend.