What is a VPN?

A VPN (Virtual Private Network) is a service that encrypts your internet traffic and routes it through a remote server, hiding your real IP address and location. VPNs were originally built for corporate security, but are now widely used for personal privacy, bypassing geo-restrictions, and masking online activity.

How does a VPN work?

When you connect to a VPN, your device creates an encrypted tunnel to a VPN server. All your internet traffic travels through this tunnel before reaching its destination. The process works in four steps:

1. Authentication: Your VPN app connects to a remote server and verifies your identity using login credentials or a digital certificate.
2. Encryption: A secure tunnel is created. Your data gets encrypted (typically with AES-256, the same standard governments use for classified data) before leaving your device.
3. IP masking: When your traffic exits the VPN server, it carries the server’s IP address instead of yours. Websites see the VPN server’s location, not your real one.
4. Return path: Responses from websites travel back through the same encrypted tunnel to your device.

The result: your ISP cannot see what you browse, websites cannot see your real IP, and anyone intercepting traffic on public Wi-Fi only sees encrypted data.

From a network perspective, the exit IP often belongs to a hosting or colocation provider, or to a dedicated block registered to the VPN brand. Analysts sometimes map those ranges using ASN and routing data. That is useful context for advertisers: a click that geolocates to a target city may still originate from infrastructure that behaves like a datacenter on other signals.

Common VPN protocols

The protocol determines how the encrypted tunnel is built. Each offers a different balance between speed and security:

• WireGuard: The newest and fastest protocol. Lightweight code, strong encryption, excellent for streaming and general use.
• OpenVPN: The most widely supported protocol. Open-source, highly configurable, and effective at bypassing firewalls and censorship.
• IKEv2/IPsec: Stable on mobile devices. Automatically reconnects when switching between Wi-Fi and cellular networks.

Corporate deployments often add always-on policies and split tunneling, which sends only work traffic through the VPN while other apps use the normal path. That matters for advertisers: your legitimate B2B buyers may permanently appear as VPN exits in another state because their company security policy requires it.

Why do VPNs matter for digital advertising?

Third-party research underscores how much automated and invalid traffic moves across the open web. CHEQ’s 2024 State of Fake Traffic report described 17.9% of analyzed traffic as invalid, up from 11.3% the year before, based on billions of data points across enterprise properties (CHEQ, 2024). VPNs are not the only cause of that bucket, but they are a common way to disguise where scripted traffic exits onto your landing pages.

VPNs play a significant role in ad fraud and click fraud. Here is why advertisers need to understand them:

Fraudsters use VPNs to disguise bot traffic. By routing clicks through VPN servers in different countries, attackers make their bot traffic appear as if it comes from your target audience. A bot in Eastern Europe can look like a potential customer in New York or Amsterdam. This makes fraudulent clicks harder for basic filters to catch.

VPN traffic skews your campaign data. When bots and fraudsters use VPNs, your Google Ads geographic reports become unreliable. You might see strong “performance” from a region that is actually generating zero real conversions, leading you to misallocate budget.

Legitimate users also use VPNs. This is the tricky part. Not every VPN click is fraud. Privacy-conscious customers, remote workers, and users in countries with internet restrictions use VPNs for everyday browsing. Blocking all VPN traffic would mean losing real customers.

This is why effective click fraud protection looks beyond just the IP address. At ClickPatrol, we analyze 800+ data points per click, including device fingerprints, behavioral signals, and network characteristics, to distinguish between a real person on a VPN and a bot hiding behind one.

A simple budget example shows why geo alone fails. Say you pay EUR 9 per click in a competitive local services vertical and you target one metro area. One hundred clicks that all exit through the same consumer VPN provider in that metro can look “on target” in a location report while still sharing automation markers in timing, device reuse, and session depth. Without cross-signals, you can burn EUR 900 on sessions that never behaved like buyers.

VPN use also interacts with proxies. Commercial VPNs encrypt and tunnel; many fraud operations pair tunneling with bot tooling so each node gets a fresh exit IP. Your risk is not the VPN category by itself; it is the combination of tunneling, shallow engagement, and repeated patterns across campaigns.

Can you block VPN traffic on your ads?

Yes, partially. Google Ads does not provide a native VPN-blocking feature, but there are practical steps you can take:

• Exclude datacenter IPs: Many VPN providers run servers in commercial data centers. You can exclude known datacenter IP ranges in Google Ads, though this is a manual, ongoing effort.
• Use third-party protection: Tools like ClickPatrol automatically detect and block VPN-based click fraud in real time, without blocking legitimate VPN users who show genuine engagement signals.
• Monitor geographic anomalies: If you see clicks from locations that don’t match your targeting, VPN-based fraud is a likely cause. Check your Google Ads vs GA4 data for discrepancies.

Blocking every VPN exit outright would also catch real buyers who work under strict privacy policies. ClickPatrol's stance on this trade-off is covered in do we block VPNs: score the session on behaviour and outcomes, not the tunnel alone.

VPN vs proxy: what is the difference?

Both VPNs and proxies mask your IP address, but they work differently:

• A VPN encrypts all traffic from your device at the operating system level. Every app, browser, and connection is protected.
• A proxy only routes traffic from a specific application (usually just a browser). There is no encryption, so your data can still be intercepted.

In the context of ad fraud, attackers use both. Residential proxies are particularly dangerous because they route traffic through real home internet connections, making bot clicks look identical to genuine user traffic.

For a broader view of tactics that pair hiding origin with scaled clicks, read ad fraud techniques in 2026 and ClickPatrol’s PPC click fraud study, which quantifies how often paid search accounts see non-human or low-quality traffic when measured with modern detection.