How To Detect And Avoid An Ad Fraud

Everybody knows that two of the biggest Internet giants, Google and Facebook, generate most of their revenue from online advertising.

Digital advertising is a cash cow for them, but for the rest of us is a way to generate website traffic, sales, and leads. But what happens when the system gets rigged by unethical players? The ones receiving the full impact of ad fraud are not the big digital giants, but the small players using digital ads as a means to develop their businesses.

This is why detecting and preventing ad fraud is fundamental for a healthy online ecosystem. Anybody can perform ad fraud detection. Even you can do it. Regardless if you are part of a Fortune 500 company, with ad budget running in the millions or small online businesses looking to get off the ground. You only need a couple of tools, by which one is free. And the process is straight-forward.

What is Ad fraud

Ad fraud is like a chameleon. It can take various shapes and forms, and to this day, it’s quite challenging to create an automatic process to detect ad fraud – it’s difficult but doable. The best ad judge remains still the human eye.

Some of the most popular ad fraud techniques:

  1. Invisible (hidden) ads – counting ads impressions that are not displayed to real users
  2. Laundering impressions – displaying advertisements on high-traffic websites that weren’t part of the advertising agreement (for example, buying ad slots for a financial website and instead of being published there, are displayed on a website with images or on an adult website)
  3. Click hijacking – when an ad is clicked a fraudulent redirect takes place, sending the user to an unwanted website
  4. Pop-under – displaying advertisements behind the browser (the user doesn’t see the ad, but the publisher charges the advertiser for the display)

There are many other ad fraud techniques with an estimate of more than $5 billion stolen by fraudsters in 2019. More info here.

Biggest ad fraud to date

You might think that ad fraud is a small-time game with a few thousand USD siphoned here and there. But how does $3.000.000 per day sound?

Unbelievably, this is the amount fraudsters used to pull from advertisers with the infamous Methbot, discovered in 2016.


They used several hundreds of servers, spread around the world, to automatically access videos and web pages loaded with ads, up to the point that it used to display 300 million video ads daily.

Ad spending in perspective

On average, 31% of users click on the ads displayed to them. This statistic makes digital advertising an exciting proposition to marketers and a gold mine to fraudsters.

This is the reason why marketers should pay attention to ad fraud and take actionable steps to detect and prevent ad fraud.

How to detect ad fraud – tools of trade

For large scale marketing campaigns, an automatic approach (although not very useful in the case of elaborate ad fraud schemes) is still viable. But for most marketers, ad fraud detection can be performed manually with a couple of tools: a web browser and proxies.

-The web browser

You need a simple web browser to access the websites where you bought ad slots to check them manually.

Any browser can be used. It’s up to your personal preference if you choose to go with Google Chrome or Mozilla Firefox. As long as the browser supports a proxy manager, such as FoxyProxy, which can be installed as a Chrome plugin or Firefox addon.


To better impersonate regular users spread around the world, you need to emulate various geographical locations scattered across the globe. You can do this with proxies. Particularly with proxy servers with residential ISPs (such as Vodafone, O2 or AT&T), like those here.

In this way, any accessed website will identify [the proxy] ISP and location and display ads for that particular area. Using a proxy IP from AT&T, San Francisco, the site will return your ads for that city.

Essentially, with the help of proxies, ad fraud detection can be performed from anywhere in the world – even digital nomads can do it – for any target location of interest.

Moreover, with the help of an user-agent modifier, like User Agent Switcher, you can also emulate mobile devices and other screen sizes. You would need this feature if you bought mobile ad spots.

Ad fraud detection success-rate

At first, performing ad fraud detection manually through a browser can seem time-consuming. But with time, once a systematic approach is set in place, it becomes easier and faster to perform. Also, one can hire a VA (virtual assistant) to complete the task.