How to How to Prevent Ad Fraud and Improve Campaign Results

Maria Chou

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Ad fraud is a big problem that’s still wasting money, messing up reports, and tricking campaign algorithms into thinking fake activity is real.

So, how to prevent ad fraud? 

Let’s start with the simple stuff: figure out what’s fake, block those fake clicks and impressions, and use cleaner ways to buy and sell ads. BidsCube has programmatic solutions that help advertisers, publishers, and AdTech partners create safer and more controlled environments for buying and selling ads. This way, everyone can trust that their ads are being seen by real people, and that their money is being well spent. By getting back to basics and using the right tools, we can make a big difference and keep ad fraud from draining our budgets. 

Losses due to digital ad fraud are expected to total $172 billion by 2028, reports Statista. Therefore, fraud prevention must become a component of serious media planning as well, as not only money is lost by digital ad fraud, but also the impairment of campaigns and the distortion of conversion data which the campaigns learn from. 

Continue reading to learn more about ad fraud in our in-depth guide. We will cover types of ad fraud, how it can affect you and your business and ad fraud protection methods with the help of AI and machine learning as well as your supply partners and more. 

What Is Ad Fraud?

Ad fraud is a form of deception that is meant to generate false clicks, impressions, conversions and traffic in order to gain ad revenue from advertisers. Most types of ad fraud use so-called bots, click farms, spoofed domains, etc., to deceive advertisers. Fraudsters get paid by the advertisers for clicks and views by from non human users. 

A useful answer to what is an ad fraud solution is simple: It is a mix of detection, filtering, verification, supply control, and reporting. One tool rarely solves the whole problem. Good protection combines analytics, ad verification, trusted partners, and supply-side controls.

Why Ad Fraud Is Dangerous

• Wasted ad spend. Companies pay for fake traffic or interactions.
• Skewed metrics. Fraudulent activity can also generate false data leading the advertiser to make incorrect marketing decisions.
• Brand reputation damage. The worst thing is that ads on fraudulent or very low quality websites can actually harm the advertiser’s own reputation. 

Common Ad Fraud Types in Digital Advertising

In short, there are five ad fraud types in digital advertising:

1. Click fraud
2. Impression fraud
3. Domain spoofing
4. Ad injection
5. Pixel staffing and ad stacking

1. Click Fraud

The most common form of digital advertising fraud is click fraud. Click fraud is defined by the generation of false clicks to online ads. These fake clicks can be produced by various methods, including by software and by humans for a payment. 

The vast majority of such clicks are used to increase the click-through rate (CTR) of online ads, which is used to gauge the success of online advertising campaigns. The majority of such cases of click fraud occur in Pay-Per-Click (PPC) advertising models where an advertiser pays for each click to online ads. 

How click fraud works:

• Fraudsters use software (bots) or click farms to generate artificial clicks on online ads.
• The fake clicks can skew the metrics for the ads, and generate false data that makes the ads seem to be getting a lot of interest. As a result, the advertiser would be paying a lot of money for clicks on their ads generated by automated programs and seen by no people.
• There are even worse cases of click fraud, where an adversary targets the ads of a competitor in order to burn through that competitor’s budget and reduce their visibility. 

Why it’s harmful:

• Wastes advertising budgets on non-existent audiences.
• Produces skewed metrics, leading to flawed marketing strategies.
• Campaign performance will be negatively affected and may result in a large decrease in ROAS.

Example: An advertiser running a PPC campaign for a new product recently discovered that there had been an unusual spike in clicks coming from one region of the world. Upon closer inspection he discovered that the vast majority of the clicks were coming from a click farm generating fake traffic to generate fake engagement to generate ad spend.

2. Impression Fraud

Most recent and widespread form of ad fraud is so-called Impression fraud. This type of fraud particularly affects Advertisers who run their campaigns on a Cost Per Thousand Impressions (CPM) basis. The fraudster wants to increase the number of impressions in artificial way in order to pretend that many more people than actually see the ad. 

How impression fraud works:

• Traffic to these sites are generated by the fraudster himself, either by setting up sites or by using bots to visit them.
• Pages are automatically refreshed so that more views are counted. Alternatively, the ad is placed so far down on a page that most users wouldn’t even see it.
• These non valid impressions are published on sites with a minimum of content or even none at all. 

Why it’s harmful:

• The number of people who have seen the ads is inflated, so the advertiser believes he or she is reaching a larger audience than they actually are.
• These Impressions have no value to the advertiser as they are generating no conversions / sales etc.. Meaning a lot of money is being spent by the advertiser in sending their ads to worthless Impressions.
• Reduces campaign efficiency and distorts analytical reports. 

Example: A video advertising campaign operating off of a CPM basis suddenly starts delivering millions of impressions overnight. Engagement of users with the advertising content however is very poor. Bots are auto-refreshing pages in order to generate fake impressions for inflated reporting. 

3. Domain Spoofing

With domain spoofing, ad fraudsters mislead the market and get paid for low-quality domains by pretending they are premium domains. 

How domain spoofing works:

• By manipulating the Ad Exchanges and the Supply-Side Platforms, the fraudster can present his inventory of low quality sites in a misleading manner as if they were high value sites, so called premium domains.
• These ads are supposed to be displayed on high end websites such as CNN or The New York Times. Instead, they get published on completely unrelated websites, such as clickbait websites.
• The publisher (ad fraudster) is paid for all the served impressions to fake audiences (never seen by real human beings).

Why it’s harmful:

• Money is being wasted by being displayed on low quality sites with no relevant audience.
• This type of activity can also have very adverse affects to a brand as they could be publishing their messages on sites of very poor quality or even worse still – totally objectionable.
• This type of fraud negatively impacts the efficiency of an advertiser’s spend as well as their ability to accurately measure and report the performance of their campaigns. 

Example: A luxury car brand recently discovered that their online ads were being displayed on some low quality clickbait sites instead of the high end automotive sites that they had been targeting. With the aid of the domain spoofing detection tool provided by us the online ad fraud was soon discovered and halted. 

4. Ad Injection

Ad injection is another form of ad fraud that is added to web pages by third parties through means of malware, malicious browser extensions or even malicious mobile applications. In most cases, they are injected to high traffic websites in order to intercept ad revenue that would otherwise be displayed by the website’s current ads. 

How ad injection works:

• Malware on a user’s device, or even a browser extension that the user has added to their browser, can alter the user’s browsing experience in order to generate additional revenue from the legitimate advertising that the web page is displaying.
• In most cases, these ads are irrelevant to the content on the website and can cause great annoyance to web surfers.
• A host of irrelevant ads can be superimposed on a legitimate webpage and obscure its content.

Why it’s harmful:

• Damages user trust and creates a negative experience.
• Steals revenue from legitimate publishers.
• The risk of being associated with poor quality content and/or unwanted ads. 

Example: An e-commerce website has been affected by unauthorized third-party ads injected onto the website. These ads are typically injected by malware on the visitor’s computer or by malicious browser extensions. 

5. Pixel Stuffing and Ad Stacking

These types of fraud can be used to generate a high amount of ad impressions with little to no user engagement. They can vary in methodology but generally are used to deceive the advertiser by reporting false statistics. 

Pixel Stuffing:

• Pixel stuffing involves placing a small 1×1 pixel ad behind other graphics and elements on the page. The purpose of the small pixel ad is to count impressions for the ad space and usually the publisher is using this tactic for CPM campaigns where more impressions can translate into higher earnings. 
• This type of fraud is typically found in CPM campaigns, where the publisher is paid for every impression. 

Ad Stacking:

• In Ad Stacking, several ads are stacked on top of each other. On the surface level, it may appear as though only the topmost ad can be viewed by the user. However, all of the ads that have been stacked are counted as impressions.
• All of the ads that are stacked on top of one another are reported as impressions, even though the only ad that is visible to the user is the ad on top of the others. 

Why they’re harmful:

• Inflate impression counts and reduce ad quality.
• Drain ad budgets without delivering meaningful results.
• Reporting completely inaccurate numbers to give the appearance of user engagement. 

Example: A publisher has set his site to maximize CPM. He checks his numbers to see them fall dramatically. After attempting to troubleshoot the decline, he finds that his ads are being rendered as stacks of multiple frames each serving for multiple impressions. 

In extreme cases he finds that he has actually been served an “ad” that is a single, tiny, nearly invisible pixel that will serve for many impressions before being refreshed with a new (also nearly invisible) pixel to again serve many more impressions then a normal sized ad space would serve. 

This table also helps explain ways to prevent digital ad fraud without turning the section into a long checklist.

The Financial Impact of Ad Fraud on Businesses

If a reader asks how does fraud affect advertising, the answer goes beyond wasted media spend. Fraud corrupts data, weakens bidding algorithms, hides real audience behavior, and makes budget planning less reliable.

Performance marketing fraud is especially damaging because optimization systems learn from false signals. A campaign can look busy while producing no real customers.

How to Detect Ad Fraud in Your Campaigns: Four Key Steps

Keep the four existing steps, but update the tools section and add the keywords below naturally.

Monitoring analytics and conversion rates should sit at the center of your ad fraud detection techniques. These metrics should be individually reviewed for device, geography and publisher. Alerts for sudden spikes in CTR, bounce rate, conversion rate, viewability and traffic source mix are important to know how to stop ad fraud before it’s too late. 

Step 1. Monitor Analytics Regularly

The best way to combat digital ad fraud is to monitor your analytics data to pick up on any unusual activity early on to prevent any significant losses. 

What to Look For

• Unusual traffic spikes. Sudden influxes of traffic from specific countries, or from certain devices can also highlight cases of fraud. 
• High bounce rates. Most fraudulent traffic is ‘transient’ in nature – it ‘enters’ and then ‘exits’ your web site immediately, thus causing a ‘spike’ in the bounce rate from a given traffic source. 
• Inconsistent engagement metrics. High click through rates (CTRs) that do not translate into higher conversion rates are another sign of click fraud. 
• Traffic from unexpected sources. Traffic from non targeted traffic sources could be indicative of fraud as well. 

Pro Tip: Set up unusual traffic activity alerts and review your Google Analytics or other ad platform reporting on a regular basis to detect potential ad fraud before it’s too late and causes too much damage to your budget. 

Step 2. Analyze Conversion Rates

Conversion rates are also a metric that you should pay attention to in the context of your advertising fraud detection. As with other types of fraud, the people trying to carry out ad fraud will usually try to manipulate numbers in order to cover their tracks. However, if you know what the typical rates are for your ads, then you can spot any unusual activity more easily, for example if your normal conversion rate suddenly plummets for no apparent reason and no changes have been made to the ads or the campaigns. 

What to Check

• CTR vs. conversion rate comparison. A high CTR coupled with an extremely low conversion rate is a common sign of fraudulent traffic.
• Sudden drops in conversion rates. Identifying unusual patterns in your campaign conversion rates. For example, a sudden drop in conversion rates for your campaign. 
• Mismatch between impressions and conversions: High numbers of impressions with low conversion rates could indicate the occurrence of Impression Fraud. 
• Unusual patterns in sales funnels. If users abandon their journeys at the same point every time, it may indicate automated traffic.

Pro Tip: Use the tracking of conversions that we set up via our conversion tracking tools, such as Google Analytics or Facebook Analytics, or other 3rd party tools. We then compare the relevant metrics such as CTR and conversions to see if there are any issues. 

Step 3. Use Ad Fraud Detection Tools

By using specialized tools for the detection of invalid traffic and for the measurement of media quality, serious losses due to fraud can be prevented before they even occur. Click analysis, for instance, can be used to identify suspicious behavior. Moreover, impression fraud can be investigated by the use of appropriate tools as well as bots and other non-human entities. The measurement of viewability and the scoring of domains and traffic-sources are further indicators of ad fraud detection techniques that are used by the aforementioned tools. 

Popular Tools to Consider

1. DoubleVerify:

DoubleVerify is still a leading provider of ad verification and media quality solutions. It helps to identify and prevent ad fraud and also detects and filters invalid traffic. They monitor all formats of online advertising, including desktop, mobile web, mobile apps and CTV. They can also help advertisers avoid buying ‘bad media’ before their competitors do. DoubleVerify solutions can be deployed pre-bid in programmatic ad buying to filter out ‘bad media’ before it’s bought by the advertiser. 

2. HUMAN, formerly White Ops:

After their rebranding in 2021, White Ops now is known as HUMAN. HUMAN is leading company in Bot Detection & Prevention of Fraud for Advertising, Applications, Accounts & Transactions. Their solutions are protecting online transactions and user interactions all over the world to secure them from potential fraud. For detection and prevention of Ad Fraud, HUMAN is supporting platforms and advertisers to detect and prevent non-human traffic as well as behaviors and signals of poor quality. 

3. TrafficGuard:

TrafficGuard remains active as a click fraud and invalid traffic prevention platform. Click fraud and invalid traffic prevention in real time for Google Ads, Meta, affiliate programs and user acquisition for mobile apps. 

4. Forensiq, now part of Impact:

The technology behind Forensiq was acquired by Impact Radius in 2016 as part of their larger fraud detection and partner management strategy. To this day, traffic quality and a host of other fraud detection signals are still built out by the team at Forensiq as part of the larger Impact platform, utilizing a host of machine learning to identify and flag suspicious behavior on a granular level. 

Pro Tip: Another danger for advertisers is becoming dependent on one person or one tool to do all the ad fraud fighting for you. This can lead to ignoring other simple tactics that would also detect and prevent fraud such as: using ad verification services, blocking of invalid traffic on ad exchanges, monitoring of Impressions / Clicks / Conversions, checking Ads.txt and sellers.json, and reviewing of SSP settings and of direct supply (publishers). 

Step 4. Employ Third-Party Auditing

Even with the best fraud detection methods in place, no one is perfect and that’s why third-party auditing of your campaigns can be an added layer of security for you. 

Why Use Third-Party Audits?

• Unbiased analysis. An independent auditor has no influence of internal bias which means they can provide you with an honest transparent view of your traffic sources. 
• Identify vulnerabilities. A third party audit can uncover areas of weakness within your ad placements and traffic sources. 
• Enhanced reporting. Advertisers can get detailed reports from auditors about the traffic sources that were tested and the quality of their campaigns. 

How Audits Work

1. Auditors examine your campaign’s traffic logs, user interaction patterns, and performance metrics.
2. The auditor will compare your campaign’s traffic and user behavior to typical traffic and behavior for legitimate users. 
3. Comprehensive reports are provided, allowing you to act on verified findings.

Pro Tip: Performing audits on a regular basis, especially after launching big campaigns, will help you to identify and stop fraudulent traffic in time to avoid any damage. 

Fraudulent activity in the world of online advertising is a serious and ongoing problem but can be managed through a variety of different tools and methods. Information from a variety of data sources and from your analytics packages can be used in conjunction with a variety of specialized software and also with third-party audits of your campaign(s). 

But at the end of the day, it is perhaps the most basic piece of information about your campaign – i.e. where your traffic is coming from. That will allow you to tackle the biggest problems and identify instances of fraudulent traffic that could have serious, long-lasting consequences for your wallet. 

Best Practices for Advertisers to Minimize Fraud Risk

The best practices for avoiding fraud in paid ads campaigns start with partner quality. A strong ad fraud prevention solution should not only detect fraud after spend is lost. It should also reduce exposure before bids happen.

Five Effective Strategies for Reducing Ad Fraud

Here are five strategies to build a solid foundation for reducing ad fraud:

Strategy #1. Choose Trusted Ad Networks

Work with partners that explain their traffic sources, fraud controls, and reporting standards.

Practical example: Ask each network for traffic source rules, refund policy, and IVT handling before launch.

Strategy #2. Implement Ads.txt

You can find a publisher’s Ads.txt file, which lists all sellers that are approved to legally sell that publisher’s ad inventory. 

Practical example: For premium publisher buys, it’s a good idea to compare the seller path with the publisher’s Ads.txt file for scaling spend. 

Strategy #3. Monitor Campaign Metrics Regularly

Also measure CTR, conversions, viewability and/or bounce rate and the split between desktop and mobile. 

Practical example: When analyzing the performance of different placements, be sure to take a close look at the click through rate (CTR) and the resulting conversions for each. 

The example above highlights a placement that received 10 times the clicks of other comparable placements but ultimately failed to generate any conversions. This placement would likely be a good candidate for further investigation and potential removal from your media buy. 

Strategy #4. Whitelist and Blacklist Domains

Use approved domains and block suspicious traffic sources.

Practical example: Build an allowlist for premium placements and block domains with repeat IVT issues.

Strategy #5. Educate Your Team

Media buyers, analysts, and Ad Ops teams should understand ad fraud protection methods. 

Practical example: In your weekly campaign report, make sure to outline what you think could be fraudulent activity in your campaigns. 

Strategy #6. Use a Trusted SSP

A quality SSP can help reduce domain spoofing, invalid traffic, and impression fraud detection gaps. BidsCube SSP gives publishers and partners more control over inventory, demand access, and reporting.

Practical example: Use SSP-level reporting to compare bid rate, win rate, CPM, and traffic quality by partner.

Strategy #7. Implement Supply Path Optimization

Supply path optimization reduces unnecessary resellers and weak traffic paths. It can help minimize digital ad fraud by cutting unclear inventory routes.

Practical example: Route spend through fewer verified sellers and compare CPM, viewability, and conversion quality.

These steps support digital advertising fraud prevention without killing legitimate reach.

The Role of AI and Machine Learning in Fighting Ad Fraud

AI can support ad fraud mitigation when the system has enough clean data to learn real user behavior. Real-time analysis can detect sudden traffic spikes. Behavioral analysis can separate normal users from automated sessions. AI Pattern Recognition (such as machine learning algorithms) can identify similar fraud occurrences across many different data points such as devices, locations and supply sources. 

How AI and Machine Learning Combat Ad Fraud

AI and ML offer these important tools to combat ad fraud:

1. Real-time analysis. Machine learning can be particularly powerful in differentiating human behavior from non-human behavior by understanding large amounts of data about typical user behavior and online session activity, including how users interact with web pages and online content including how they scroll, click etc.
2. Behavioral analysis. Machine learning algorithms excel at distinguishing genuine user behavior from automated bots. By analyzing user interactions, such as scrolling, clicking, and session duration, AI tools can quickly detect non-human activity.
3. Pattern recognition. As the system learns from previously identified attacks, it will be able to recognize these types of attacks in future and block them for the advertiser. Each update of the system will ensure that the system’s accuracy and efficiency are continually improved. 
4. Predictive fraud scoring. ML models can score impressions, clicks, and traffic sources before they damage a campaign. This helps teams with ad fraud mitigation earlier and shows how to improve ad performance by blocking fraud before budgets move to weak traffic.

Publisher Prevention of Ad Fraud: How SSPs Can Help

Publishers need publisher prevention tools that preserve revenue, not tools that block too much good traffic. The right SSP that can help reduce ad fraud and still keep strong cpm should filter low-quality traffic while keeping trusted demand active.

For advertisers asking how to stop ad fraud and ensure their advertising budget is spent on legitimate traffic, SSP quality matters because fraud often enters through weak supply paths. For publishers asking, what are the best ways to reduce ad fraud and invalid traffic to protect revenue, the answer starts with supply controls.

Core SSP mechanisms include:

• Invalid traffic (IVT) filtering before and after bids

• Brand safety controls for unsafe content

• Ads.txt validation and sellers.json checks

• Traffic scoring and blocking suspicious DSPs

• Real-time CPM monitoring to protect yield

BidsCube SSP can support publisher-side controls for inventory, reporting, and demand connections.

Multinational Ad Fraud Prevention: Challenges and Solutions

To manage this, advertisers need strategies to reduce ad fraud without losing revenue. Use local benchmarks for CTR and conversion rate. Split reports by GEO, device, and seller. Apply stricter checks to new regions before scaling spend. Use brand safety and partner quality rules for every market.

Final Thoughts: Strengthening Your Advertising Security

The battle between advertisers trying to protect their campaigns from fraud and clever fraudsters trying to maximize their return is a constant one. By learning how to protect yourself from different types of online advertising fraud, using the right tools and following best practices to prevent it, you can save millions of dollars. 

Key insights to remember:

• Ad fraud encompasses many different behaviors that are considered to be deceptive in order to trick advertisers into paying for invalid or fake impressions and/or clicks. There are two main categories of ad fraud: click fraud and/or impression fraud that is generated by bots or by people from click farms and other types of fraud such as domain spoofing and ad injection.
• As much as we at AdFox hate to say it, in 2025 due to the inactivity of the ad industry, companies will lose over $100,000,000,000 annually as a result of fraud. However, with the right tools at your disposal, millions can be saved.
• Review campaign data, compare the key performance indicators (KPIs) of various campaigns and incorporate advanced detection technology (e.g. DoubleVerify, MOAT, TrafficGuard).
• Some of the ways to protect yourself from losing money to fraud is using tools like Ads.txt, supply path optimization, working with only verified publishers. Also, it’s very important to an eduate your own teams to help mitigate potential risk of fraud.
• Ad Fraud Detection & Prevention with AI & Machine Learning currently is the most advanced approach to detect and prevent online Ad Fraud in real-time while advertising online. 

So while there is ad fraud present it can be combated with proactive strategies and evolved with the latest in AI and machine learning. It is key for advertisers to stay up-to-date on the latest in fraud prevention in order to get the most out of their marketing budget. 

Ad fraud will not disappear, but better controls can reduce its damage. BidsCube helps publishers, advertisers, and AdTech partners build cleaner programmatic paths through BidsCube SSP, BidsCube DSP, and BidsCube White-Label AdExchange. 

For broader vendor checks, review BidsCube on Clutch, then contact us to discuss our fraud filtering SSP and traffic quality controls.

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FAQs

What Is Ad Fraud and How Does It Work?

Online advertising fraud is designed to extract as much money from the ad budgets of the advertisers as possible. Most of these types of online advertising fraud make use of so called bots, click farms or other types of invalid traffic (IVT) in order to achieve their advertising objectives. 

What Are the Most Common Types of Ad Fraud?

Examples of typical Ad Fraud methods include: click fraud, impression fraud, domain spoofing, ad injection, pixel stuffing and ad stacking. 

How Can I Predict Ad Fraud in My Campaigns?

You can use the following methods to prevent and predict ad fraud in your campaigns: trusted partners, IVT filtering, ad verification, Ads.txt checks, supply path optimization and campaign audits. 

What Are the Best Prevention Tools for Ad Fraud?

There are many solutions out there that deal with ad fraud for online video (e.g. HUMAN, DoubleVerify, TrafficGuard, Forensiq by Impact and others), display and mobile (same providers listed above), as well as for supply-side platforms (SSP-level filters, third-party audits by for example Moat). The best solution for a campaign depends on the advertiser and the objectives of the campaign. 

How Does Impression Fraud Affect CPM Campaigns?

Impression fraud most seriously affects CPM campaigns by reducing the actual number of people that are exposed to an ad. The value of a CPM campaign is decreased dramatically as advertisers are paying for views of an ad that have not been seen by real people. The effects of impression fraud can also be tracked in campaign performance reports. 

How Can an SSP Help Reduce Ad Fraud and Preserve CPM?

An SSP can enable a publisher to filter out invalid traffic using IVT filters. SSPs can also verify the inventory for sale from publishers. They can also use supply path optimization to ensure that only the best supply paths are used. Additionally, an SSP can provide reports on CPM in real time, enabling publishers to compare the performance of different pieces of ad space and see where they are getting the greatest return on investment. 

What Is the Difference Between Click Fraud and Impression Fraud?

Unlike Click Fraud which is typically charged on a CPC basis and is therefore often counted to create additional expense for the advertiser (i.e. creating artificial clicks), Impression Fraud is designed to create false views of a publisher’s inventory. Impression Fraud is therefore typically counted and billed as false impressions to the advertiser.