Here’s a fun fact:

Only 27% of all marketing-generated leads are actually sales-ready. And 80% of marketing leads never convert into sales.

If your first instinct is to pin this (frankly depressing) stat on a lack of lead nurturing, or a poor lead gen strategy—well, you could be right. But it’s likely not the whole picture. 

Even businesses with the most well-versed lead gen strategies still see a significant number of spammy, low-intent leads that waste time, muddy data, and eat into budgets. 

So where exactly are these spam leads coming from—and more importantly, what can you do to prevent them?

In this article, we’ll break down why fake leads are becoming so prevalent, how they impact your business, and the actionable steps you can take to clean up your lead gen efforts.

Why are you getting spam leads?

Spam leads don’t happen by accident. They stem from various sources, with various motives—and understanding them is the first step to stopping them. 

Let’s take a deeper look at the most common causes of spam leads:

1. Ad fraud and bot traffic

Ad fraud is a multi-billion dollar industry. Fraudsters use automated bots to interact with your ads, filling out lead forms to mimic genuine human behavior, and draining your ad spend without any real customer intent. This leads to inflated conversion rates and misleading data.

And the ad fraud problem is only growing. For the first time in history, bots have overtaken humans as the largest % of web traffic. Great news for all robot-kind, but frankly terrible news for lead gen efforts.

This momentous shift has serious implications for marketers and advertisers. And advancements in LLMs and AI agents are only accelerating this, with data from Designrush suggesting that AI scrapers and bots inflated ad costs by up to $238.7 billion in 2024.

So, while your campaigns might look like they’re performing well on the surface—with plenty of clicks, form fills, and conversions—the reality could be much less promising. That spike in traffic? It might not be your next customer. It’s now more likely than ever to be a cleverly disguised bot.

2. Click farms and low-quality paid engagement

Not all spam leads come from bots. Sometimes, they’re submitted by real people—hired through click farms, or shady lead generation schemes that promise companies “leads”—for a significant cost. (You likely already know this, but paying these “companies” for “leads” is always a terrible idea)

These operations are often paid based on volume, not quality. So, their goal isn’t to connect you with actual prospects, but to churn out as many form fills as possible, regardless of intent or accuracy. 

To you, it looks like your campaign is generating interest. In reality, your CRM fills up with junk—non-existent contacts, unreachable emails, and phone numbers that go nowhere. It creates noise in your pipeline, wastes your sales team’s time, and ultimately drains your ad budget with nothing to show for it.

For the fraudsters behind these schemes, it’s all about profit. They get paid for each “lead” they deliver—even if it’s completely worthless to you.

3. Competitor clicks and form submissions

In some cases, spam leads are more than just an annoyance—they’re a targeted tactic. Competitors may deliberately submit fake forms through your ads to exhaust your marketing budget, skew your performance metrics, and disrupt your sales funnel.

This shady practice is more common in highly-competitive industries, such as legal services, finance, real estate, and SaaS—where customer acquisition costs are high and every qualified lead counts.

By inflating your lead volume with bogus submissions, competitors can make your campaigns appear more effective than they are, leading to bad optimization decisions and wasted spend. 

Competitors will often use bot farms, but some opt for the manual approach—especially when you have high CPCs. Manual malicious engagement is harder to detect than typical ad fraud, but just as damaging. And without proper traffic filtering and IP validation in place, it’s easy for bad actors to slip through unnoticed.

4. Unqualified users

Not all spam leads are the result of intentional fraud. Sometimes, unqualified users—those with no genuine interest in your product—fill out forms due to misaligned targeting or incentivized sign-ups (e.g. free trials or lead magnet downloads). 

While there’s less malicious intent, unqualified users still contribute to muddied metrics, and wasted sales time just as much as malicious fake leads. 

Lead quality is one of the biggest marketing challenges faced by B2B companies, with over 42% of businesses reporting issues related to unqualified, low-quality, or irrelevant leads. Spam leads aren't just a fraud issue, but also a fundamental marketing challenge.

The commercial damage of fake leads

Now we’ve discussed the how and the why, let’s talk about the impact fake leads have on marketers, sales teams, and ultimately entire companies:

Wasted ad spend

You’re paying for clicks and conversions that will never turn into customers. This means your cost-per-acquisition (CPA) skyrockets, making your campaigns look far less efficient than they really are.

Sales team burnout

Your sales team spends valuable time chasing fake or low-quality leads instead of nurturing real prospects. This results in frustration, lower productivity, and missed opportunities. 

As mentioned earlier, 80% of all marketing-qualified leads (MQLs) will never convert—a stat that is significantly impacted by the number of fake or low-quality leads, which ultimately reduces overall efficiency and lowers morale. 

Distorted performance metrics

When spam leads flood your CRM, they don’t just waste your sales team’s time. They warp the important data you rely on to make strategic decisions. 

Metrics like conversion rate, cost per acquisition (CPA), and return on ad spend (ROAS) become unreliable, making it difficult to tell what’s actually working. Campaigns that appear to be high-performing on paper might be inflated by fake form submissions, leading to overinvestment in channels or messages that aren’t truly driving real customer interest.

Aside from affecting marketing efficiency, distorted performance metrics can have long-term ripple effects across businesses. A study by Validity found that 50% of businesses report losing new sales because their CRM data is outdated, misleading, or riddled with errors.

If you can’t trust your data, you can’t accurately forecast revenue, prioritize prospects, or tailor your messaging to real customer needs. In short, it’s frustrating when spam leads clog up your pipeline, but it’s business-critical when they undermine your ability to grow.

Damaged email deliverability

Many fake or low-quality leads come with invalid, mistyped, or throwaway email addresses. When your campaigns hit these bad addresses, they bounce. And too many bounces signal to email providers that you’re not maintaining a clean list or following good sending practices.

As a result, your sender reputation starts to decline. This means your future emails are more likely to land in the spam folder—or be blocked entirely—regardless of how relevant or valuable your content is. 

Even your legitimate subscribers may stop seeing your emails in their inbox, leading to lower open rates, fewer conversions, and a weaker relationship with your actual audience.

It doesn’t stop there. If your domain reputation takes a hit, it can impact all outbound communication, not just marketing emails. This includes transactional messages, sales outreach, and customer support—any area where reliable email delivery matters.

Protecting your email deliverability means keeping your CRM free of junk data and verifying email addresses at the point of capture. Otherwise, spam leads have the potential to muzzle your email channel.

How evolving fraud techniques are making the spam lead problem worse

While companies are working to overcome the fake lead problem, fraudsters are getting smarter.

Google’s automated fraud detection tools can filter out the most basic forms of invalid traffic (IVT), but they tend to miss more advanced threats. Sophisticated Invalid Traffic (SIVT) uses deceptive tactics—like emulating human behavior, mimicking mouse movements, or using residential IP addresses—to accurately mimic genuine users. These methods make it far more difficult to detect and block at scale.

In our analysis of IVT within the financial services sector, a significant 78% of all detected IVT fell into the SIVT category—highlighting just how prevalent and evasive this type of fraud has become.

The problem is only expected to worsen, as advancements in AI and automation are making fraudulent activity harder to detect and more sophisticated than ever:

• AI-generated bots can now mimic human behavior, making traditional detection methods less effective.
• Machine learning-driven fraud networks are capable of analyzing basic detection systems and adjusting their tactics in real time to evade discovery.
• Deepfake technology is starting to be used to generate realistic identities, further complicating lead verification.
• Bad actors are using AI to auto-fill forms with seemingly real information and bypass simple detection techniques like CAPTCHA.

According to a study by Imperva, AI-driven fraud attempts have increased by 27% year over year, showing a clear trend of escalating complexity and scale. 

Without advanced automated solutions, businesses will struggle to keep up with increasingly deceptive traffic moving forward, and the spam lead problem will only grow.

How to prevent spam leads and clean up ad traffic

The stats and points discussed above have painted a dire picture for the future of lead generation. 

But there is hope. Even with notable advancements in sophisticated invalid traffic and other types of ad fraud, steps can be taken to significantly reduce the impact of spam leads. 

Stopping spam leads requires a combination of proactive filtering, smarter targeting, and automated protection. Here’s what you can do:

1. Tighten your lead forms

Your lead form is typically the first point of contact between your brand and a potential customer, but it’s also the first target for spam submissions. Optimizing your forms for quality over quantity can make a big difference:

• Use advanced reCAPTCHA - Modern bots can bypass basic CAPTCHA challenges. Upgrading to Google’s reCAPTCHA v3 or invisible CAPTCHA helps detect suspicious behavior in real time without adding friction for legitimate users.
• Add friction for fraudsters - Include custom fields that require effort or context only a real prospect would know, such as industry-specific questions or drop-downs that bots can’t easily auto-complete.
• Verify email addresses - Implement email verification at the point of form submission. This ensures only valid, correctly formatted addresses make it into your CRM, reducing bounce rates and protecting your email reputation.
• Limit disposable emails - Use tools to block submissions from temporary or disposable email domains often used by spammers and fraudsters.

2. Refine your targeting strategy

Even the most secure forms won’t help if your ads are being shown to the wrong audience. Spam leads often originate from poor targeting practices that open the door to low-quality or fraudulent traffic:

• Exclude high-risk regions - Certain geographies are hotspots for click farms and lead fraud. Review your geographic data and exclude areas that consistently deliver poor-quality leads.
• Make use of first-party data - Use your existing customer data to build custom audiences and lookalike segments, ensuring your ads are served to people who closely match your best customers.
• Tighten audience demographics and interests - Broader targeting increases reach—but also risk. Narrowing your targeting to focus on specific industries or behaviors improves both lead quality and intent.

3. Monitor traffic quality with analytics

Prevention is important, but ongoing monitoring is equally essential. Analytics tools can help you spot the red flags of invalid traffic before it becomes a serious problem.

• Watch for high bounce rates - A sudden spike in bounces or very short session durations may indicate non-human traffic or disengaged click farm activity.
• Track repeat submissions - If you’re getting multiple leads from the same IP address or device fingerprint, it’s likely fraud-related.
• Analyze lead-to-customer ratios - A growing gap between the number of leads and actual sales conversions is a key indicator of declining lead quality. Use this data to revisit your targeting and lead sources.

4. Block known fraudulent IPs and sources

Once you’ve identified patterns of bad traffic, take action to shut it down at the source.

• Block suspicious IPs and user agents - Set up rules in your ad platforms or analytics tools to block repeat offenders. (Tip: AbuseIPDB.com is a great free resource to cross-reference known bad quality IPs)
• Exclude traffic from data centers - Many bots originate from hosting providers or cloud services. Filter out traffic from known data center IP ranges.
• Avoid low-quality placements and use negative placement lists - Monitor your ad placements and exclude apps, sites, or networks that consistently drive invalid clicks or fake form fills. (Tip: make use of our free 40k PMax exclusion list and our 100k Google Ads Display Network exclusion list to automatically exclude prominent low-quality placements and improve performance) 

5. Use Lunio to prevent fake leads automatically

Manually filtering out fake leads and their sources is time-consuming and reactive. For a more proactive, scalable solution, you’ll need a tool designed specifically to combat click fraud and invalid leads. 

Lunio uses advanced machine learning algorithms to effectively detect and prevent invalid clicks, and the spam leads that often follow on from them. Lunio works using:

• Real-time protection - Lunio’s AI-driven detection system monitors traffic as it happens—blocking fake clicks, form submissions, and spam leads before they hit your analytics or CRM.
• Behavioral analysis - Rather than relying on IP blacklists alone, Lunio analyzes on-site behavior to differentiate between real users and sophisticated bots or click farm workers.
• Smart exclusions - Automatically exclude poor-quality traffic sources from your campaigns, ensuring your budget is only spent on genuine, high-intent users.

Canto, a digital asset management platform, used Lunio to clean up their inbound pipeline—preventing thousands of fake leads and significantly improving the efficiency of their sales team. By eliminating noise in their CRM, Canto was able to focus only on high-quality prospects, shorten response times, and ultimately close more deals—resulting in a $350,000 pipeline increase in the first two months.

"Since making the changes Lunio recommended, the issues we were having with lead quality have improved massively. We generated more qualified pipeline in the two months after switching on traffic protection than we had done in the previous two years"

- Mandee Richards, Head of Marketing at Canto

Using Advanced Campaign Analytics to identify and eliminate spam leads at the source

If you’re serious about stopping spam leads, blocking individual IPs or tightening your forms is just the beginning. True protection against spam leads requires visibility into where the bad traffic is coming from, and that’s where Lunio’s Advanced Campaign Analytics come in.

This feature gives you a clear, campaign-by-campaign view of where invalid traffic is entering your funnel across all major ad platforms—not just Google. 

Instead of relying on account-level summaries or abstract health scores, you can dive deep into specific campaigns and uncover exactly which channels, keywords, placements, locations, or time slots are driving high volumes of spam.

Here’s how Lunio’s Campaign Analytics helps reduce spam leads:

• Pinpoint high-IVT campaigns so you can quickly spot which efforts are attracting bots or fraudulent users.
• Identify the root causes of bad traffic—from underperforming keywords to placements associated with click farms—so you can cut them off at the source and stop them from entering your sales funnel. 
• Monitor trends over time, making it easy to see if your traffic quality is improving or declining after making changes.
• Calculate wasted spend at the campaign level, helping you understand the financial impact of invalid traffic and justify reallocation of budget to higher-performing campaigns that generate the highest-intent leads.

With these insights, you can take proactive steps to improve lead quality, reduce spam submissions, and make sure your team is focusing only on the prospects that matter. Plus, the data is exportable for easy integration into external reporting tools, so you can bring clean traffic metrics into your broader marketing analysis.

In short: more transparency, better decisions, fewer spam leads.

Final thoughts

Spam leads may seem like just a minor inconvenience, but the financial and operational impact on businesses is real. Whether it's wasted ad spend, lost sales opportunities, or skewed performance data, ignoring the problem inevitably leads to long-term revenue damage.

By taking proactive steps and using solutions like Lunio, you can reclaim control over your ad traffic and focus on connecting with real potential customers.

Get a free 14-day traffic audit to see how much of your traffic is invalid—and start protecting your campaigns from fake leads.