Cause of invalid clicks?

[Curiosity]

My site gets one or two invalid clicks a few times a week. This seems like a too-frequent occurrence for my low-click-volume site, but Adsense hasn't sent me any warning letters. (I recently emailed AdSense about possible invalid clicks because my CTR skyrocketed, but they said that everything was hunky dory, so I'm not just going on supposition.)

My questions are: Is this a normal level of invalid clicks? What could be causing them? And should I be concerned?

[sailorjwd]

A few invalid clicks a week? You must be kidding.

I'm sure a lot of people here get a few invalid clicks each hour.

Just curious as to how you know they are invalid?

[Zygoot]

How do you know that your site gets invalid clicks?

[Curiosity]

A few invalid clicks a week? You must be kidding.
I'm sure a lot of people here get a few invalid clicks each hour.

Is that so? Then that's encouraging. The main time we hear about invalid clicks is when someone gets banned for them, so I don't have any other means of comparison.

Just curious as to how you know they are invalid?

My site gets few enough clicks across narrow enough channels that $0.00 clicks are often obvious from looking at the channel stats.

[Atticus]

Are there other reasons for $0.00 clicks? Are there countries from which G will not accept traffic? What if an ad is clicked when the page is displayed in the cache of a search engine -- do they pay for that?

[driris]

last week i also recieved invalid clicks on one of my channel and i sent email to google . after 2 days i again notice invalid clicks on same channel.i have not yet recieve response from g .but it is very rare to see 00 earning in channel reports.

[creative craig]

I have had lots of clicks that show nothing earned before. Nothing to worry about as it does not necessarily mean anything dodgy going on.

[entropicus]

just curious: how you determine invalid clicks by channel reports?

[Pirate]

Could be charity ads for a small part of your traffic. Maybe there isn't ad inventory for a specific niche (channel) on your site for a specific traffic origin.

[Jay27]

Are there countries from which G will not accept traffic?

Why? the advertisers decide for which countries their ads will be shown.

[Curiosity]

just curious: how you determine invalid clicks by channel reports?

If there's only one click and $0.00 in a channel at the end of the day, then the click was probably invalid.

Slightly dodgier method: If there's, say, 3 clicks in a channel and $2.00 at the beginning of the day, and stats update regularly, then at the end of the day, if there are 4 clicks in that channel but the money hasn't gone up, there's a chance that the fourth click was worth $0.00 and thus invalid.

Could be charity ads for a small part of your traffic.

Good point. They do pop up here and there when Google's algorithm burps.