Google considers that invalid clicks are clicks that are unintentional or clicks that are coming from malicious software.

Here are examples of what Google considers to be an invalid click:

Accidental clicks that provide no value, such as the second click of a double-click
Manual clicks intended to increase someone's advertising costs
Manual clicks intended to increase profits for website owners hosting your ads
Clicks and impressions by automated tools, robots, or other deceptive software
Impressions intended to artificially lower an advertiser's clickthrough rate (CTR)

Clicks tagged as INVALID in ClickGUARD are not the same as AdWords invalid clicks!

There's a number of reasons why clicks could be tagged as INVALID in ClickGUARD and here's a few:

a click from and ad bot (Google ad bot) when you didn't prevent logging these clicks in settings - it's an invalid click that's not shown in AdWords (but it did happen) and you are not charged for it.
a click made to an ad where the IP address was previously blocked - this happens when (likely a bot) saves the ad URL and makes repetitive clicks even though new ads are not showing.
a click with a duplicate GCLID - this is the most common invalid click you'll see and it can happen when someone saves the ad URL and repetitively clicks or clicks on a search ad, does the simple browser "back" action and clicks on it again, repeating the process indefinitely.

Invalid clicks are shown as INVALID in all click reports with a distinctive color (grey):



How can you learn why a click was tagged as INVALID?

Easy, just mouse over the INVALID status and you'll see exactly why the click is invalid.

Are invalid clicks hurting your business?

Not in all cases. But remember - we're talking about clicks tagged as INVALID in ClickGUARD, not invalid clicks reported by AdWords. Those other might (and likely will) hurt you. Fortunately, as you keep using ClickGUARD the number of invalid clicks in AdWords will likely significantly decease, especially if you're using Invalid Clicks Shield.

Why doesn't AdWords prevent clicks with duplicate GCLID?

In reality they will also tag those click as invalid and either not charge you for them or refund you. But they can't really prevent them because of the way URL tracking works. If someone or something saves the ad URL (that starts with ClickGUARD's tracking template) there's nothing to prevent them or it from making repetitive clicks.

Why does ClickGUARD show clicks with duplicate GCLID?

We strongly believe you should be aware of all ad activity and this is why we log these clicks as well. Additionally, knowing exactly how many invalid clicks are coming from certain sources makes it possible to automate protection from them,