There is no getting around the fact that bot traffic now makes up a huge amount of internet activity. For the digital marketer, paid search remains one of the most reliable ways of targeting your audience of choice. But invalid traffic, or IVT —aka fake clicks, click fraud or ad fraud—is a constant thorn in the side, wasting ad spend and compounding the problem by skewing performance data. 

Prevention as part of the toolkit

Savvy marketers know that fraud prevention is part of the advertising toolkit. And as fraud prevention tools become more sophisticated, it’s becoming possible to carry out real-time page-level analysis, even before a page has fully rendered. A far cry from the traditional methods of IP address blocking or even flagging invalid clicks after the event.

But while fraud prevention tools are critical, more than ever, it’s also about knowledge of the problem and understanding how to avoid click fraud. 

We’ve put together this checklist to help you track, monitor, and prevent exposure to invalid traffic, covering all stages of the customer journey, from pre-click to on-page and the post-click analysis.

Pre-click: Fraud prevention before the page loads

Most click fraud prevention software relies on IP address blocking; building a block list of known bad actors, or tracking unusual behavior on the page, and then blocking it after the event. 

However, advanced technology is allowing marketers to stay ahead of the game, reducing their exposure to fraudulent ad placements and preemptively avoiding IVT clicks before they get a chance to even see your page.

Pre-bid filters and whitelists

Being able to screen out high-risk placements is one of the most effective ways to avoid exposure to invalid traffic. 

Apply pre-bid filters to exclude high-risk domains, apps, and maintain allowlists of verified publishers to ensure your ads appear only on trusted, relevant inventory.

Select trusted and credible partners

Unscrupulous resellers or shady RTB platforms are some of the biggest sources of low-quality traffic. So, make sure to work with advertising networks and platforms that provide full transparency over where your ads were actually delivered. 

Look out for partners that adhere to industry standards such as the Media Rating Council (MRC) guidelines or Trustworthy Accountability Group (TAG) certification. When vetting potential partners, request domain-level placement reports and clear documentation on their anti-fraud measures.

Use independent fraud monitoring

Third-party fraud prevention tools offer better tracking and filtering options, more in-depth data, and more granular controls over your traffic filters. 

Lay solid groundwork for tracking

Keep track of your traffic data by using structured campaign URLs with UTM parameters, click IDs, or unique tracking templates. Consistent, well-organised tracking not only supports campaign performance monitoring but also makes it easier to identify and isolate IVT patterns during post-click or campaign analysis.

On-page: Real-time fraud protection

Most fraud prevention tools rely on the analysis of ad traffic in real time. As clicks come through to your landing pages, these tools should be able to detect IVT behavior and prevent actions before they become a costly problem.

Use page-level IVT protection

Add a simple, fast-loading script to your landing pages that can identify non-human visitors as soon as they arrive. This type of tool checks for signs of non-human activity, such as the distinction between a “good” bot and a malicious one (ie. GIVT vs SIVT), before the page fully loads. 

This helps filter or flag potential IVT early, without slowing down the page or affecting the experience for real users.

Protect conversion actions

When it comes to checkout, signup, downloads, or any other conversion actions, providing a simple and unobtrusive step to catch bad actors is critical. Some popular methods include invisible CAPTCHA or honeypot fields, or a multi-step verification process such as email confirmation. 

Human audiences do tend to expect some type of fraud prevention step, so this is rarely a barrier to a good conversion rate. But some kind of conversion protection can make a huge difference to your exposure to fraud.

Monitor in-session behavior

Fraud prevention tools often provide session recordings to track actions such as unusual tracking patterns, inactivity or other potential bot-based activity. Spotting and blocking this non-human activity is often automated, but it can be a useful tool to follow up yourself and check session behavior.

You can also usually set up triggers to flag or quarantine suspicious visits based on certain engagement criteria.

Post-click and analytics: The follow-up 

Several analytics suites use post-click analysis to determine if invalid traffic has impacted a campaign. Advertisers should receive a credit payment to their account if IVT is detected after they have been billed, but it is still worth using an external tool to help with post-click analytics.

Some things to watch out for when analyzing your campaigns for IVT, include:

Consistency with KPIs

Click-through rates (CTR), bounce rates, time on site, and conversion rates should be reasonably consistent. Keep an eye out for unusual spikes in KPIs, especially factors such as higher CTRs with low conversions or bounce rates. While some deviation can occur, engagement spikes are one of the most tell-tale signs of bot activity.

Use bot filters and analytics

Tools such as GA4 automatically filter known bot traffic, using a list managed by the IAB. However, with fraudsters adapting and evolving every day, campaign managers might also want to add custom filtering to spot and filter suspicious traffic. There are ways to do this in GA4, but leveraging a third-party fraud prevention suite can manage much of the heavy lifting here.

Optimization and exclusion

With all this data at our fingertips, marketers have the ability to treat post-click analysis as a feedback loop. Here, we can identify sources of IVT and use this data to build exclusion lists.

Invalid traffic checklist: What to watch out for

While much of this checklist relies on your own vigilance and the tools you use, there are also checks you can do before you even start a campaign. 

These are all fraud prevention standards, or questions to ask your traffic partners as you think through your campaign strategy and performance goals:

Media Rating Council (MRC) IVT Guidelines: This set of rules was created to help reduce fake or misleading online traffic is primarily designed to make sure digital ads and website content are measured accurately. 

These guidelines, developed by the MRC in collaboration with other industry groups (like HUMAN), can help advertisers and publishers to better protect themselves from IVT and get a clearer picture of how real people are interacting with their content.

Trustworthy Accountability Group (TAG) ‘Certified Against Fraud’: Alongside MRC, the TAG Certified Against Fraud is a reliable indicator that your traffic partner has the highest standards when it comes to IVT prevention. At HUMAN, we’re proud to be ‘Verified by TAG’.

Authorized Digital Sellers (ads.txt): An initiative by IAB Tech Lab, ads.txt and app.ads.txt are simple text files designed to enable buyers to spend programmatic dollars only through channels which are explicitly trusted and authorized by the originating publisher.. Usually appended to the root URL, these lists were designed to make the programmatic ad space more transparent and trustworthy. 

Other initiatives like sellers.json and SupplyChain Object (SCO) from the IAB Tech Lab also help advertisers see who is involved in the sale of an ad impression, adding even more visibility into the ad buying process.

Knowledge in the war against click fraud

From the pre-click to the post-click analysis, staying ahead of invalid traffic and ad fraud comes down to awareness of the challenge and the knowledge to tackle the problem. Simply following this checklist can help significantly reduce your exposure to click fraud and invalid traffic.

But it’s also important to remember that online fraud, especially click fraud and ad fraud, are constantly evolving and adapting. The need for comprehensive, layered protection that analyzes the entire funnel is critical in this fight. Marketers now are aware that protection at different stages of the ad ecosystem are key to preventing bad actors, whether that’s using page-level intelligence or post-click analysis tools.
Staying ahead of evolving threats means staying informed, staying proactive and using tools such as Ad Click Defense from HUMAN, which classifies and filters bad clicks from bad actors. By adopting these best practices now, marketers can ensure their ad spend reaches real people, delivers real engagement and drives measurable results.