Last updated: 17 June 2025
Retargeting is a powerful digital advertising technique that helps businesses reconnect with a potential customer. When a user visits a website and views potential purchases without following through, retargeting ads follow them across the web, reminding them of the product or service they were seemingly interested in.
However, scammers have found ways to exploit this system, stealing billions from advertisers through retargeting fraud. Here’s how it works—and how Polygraph stops it.
How retargeting click fraud works
Fake visitors, real costs
Scammers set up genuine-looking websites and sign up as publishers on ad networks such as Google Ads, Microsoft Ads, and Meta Ads. Once approved, they can display legitimate ads on their fraudulent sites which allows them to collect revenue for worthless traffic.
The bot setup
The scammer builds a fake "user" by creating a click fraud bot. To make this bot appear as though they are a real person, they use special tools that mimic human behavior and route the bot's traffic through random home internet connections across different locations. This serves two purposes: it hides the bot's true origin, and more importantly, gives it a new "digital address" for each click. Since the bot appears to be a different user each time, simply blocking suspicious IP addresses does nothing to stop it. See why IP blocking fails against these bots.
How scammers pick their targets
The scammer researches expensive ad keywords like "NY lawyer", "online MBA", or "knee surgery". These high-value keywords earn more money per click, so targeting them maximizes the scammer's profits.
How bots mimic real users
The bot starts by searching Google, Bing, or Facebook for one of the expensive keywords, then clicks on every result - including the paid ads. To avoid detection, it behaves like a real visitor by browsing websites, filling out forms, or even adding items to carts. This sophisticated online behavior allows the fake traffic to appear legitimate.
The retargeting scam in action
Now that the advertising network believes the bot is a real user and should be retargeted, the scam enters its final phase. When the bot visits the scammer's website, the site displays a high-value ad. The bot immediately clicks this ad, generating fraudulent revenue for the scammer through the ad network - while legitimate advertisers pay for worthless clicks.
Faking conversions
To make the deception even more convincing, the bot will fake actions that look valuable to advertisers, which tricks the ad network into seeing the bot as a genuine customer. Learn more about conversion fraud.
How Polygraph helps
Polygraph detects and disables the bots responsible for retargeting click fraud, preventing them from generating fake conversions such as submitting spam leads or adding items to carts. Because ad networks optimize toward users who convert, stopping these fraudulent bot actions retrains the algorithms to prioritize real human traffic instead. This means your ads are shown to genuine customers, reducing wasted spend on bots and effectively eliminating retargeting click fraud.
In summary
Retargeting is a powerful marketing tool that shows your ads to people who visited your website. But scammers have found a way to abuse it: they trick ad networks into displaying your high-value ads on fake websites, then use automated bots to click them. This scheme earns criminals easy money while draining your advertising budget.
Polygraph stops this fraud by detecting and disabling bots before they generate fake conversions. This retrains ad networks to send you real human traffic, ensuring your retargeting budget reaches genuine potential customers.