How much money is lost to ad fraud each year?
Nobody knows precisely; published estimates range from a few billion to more than $80 billion a year depending on methodology. Juniper Research estimated $84 billion (22% of online ad spend) was lost in 2023, rising to $172 billion by 2028. Earlier ANA and White Ops studies put losses nearer $6 billion. All of these are modelled estimates, not audited totals.
The gap between estimates comes from definitions and data. Some studies count only confirmed SIVT in the campaigns a vendor measured, then extrapolate. Others model ad fraud as a share of total digital spend, including hard-to-measure areas such as mobile attribution fraud and search clicks. Juniper Research's 2023 study (produced with ad-fraud vendor Fraud Blocker) estimated 22% of online ad spend was lost to fraud; the ANA and White Ops (now HUMAN) "Bot Baseline" studies projected about $5.8 billion in global losses for 2019, after years of falling rates in the campaigns they measured.
Treat any single headline number with care: vendor-sponsored studies have an incentive to emphasize the problem, while measured IVT rate figures only reflect traffic that was already monitored. The honest summary is that fraud is large, persistent and shifting toward channels with weaker measurement, such as CTV fraud and in-app.