Clicks that will get you into trouble with Google AdSense or you are already in trouble with Google AdSense
First, the type of clicks (click fraud) listed below is definitely not a cheat list. It is the type of clicks that will let Google triggered their banning fingers. It is the reasons why Google has banned you from their AdSense program.
1. Basic innocent clicker cheat
The website owner is naive or ignorant about Internet technology, affiliate program and did not bother to read Terms of Service document (or other program policy document). He clicks on his own ads (Google AdSense ads) installed on his website. Google does not permit you to clicks ads on your own site.
2. Proxy click cheat
You are familiar with cookies and IP address or may not and make a guessed that if you use a software tool called anonymizer, Google would not be able to trace you, because your identity is obscured by the anonymizer tool. You could also be using proxy server and other rerouting software. Believe me, Google can still trace you and your clicks.
3. Multiple computer clicker cheat
Knowing that Google can smell their cookies on your computer and you are aware that Google can detect if clicks are originated from your computer. So you try to fool Google with the origin of the clicks and you asked your friends, relatives, family members, neighbors and other strange buddies to assist you on a mischievous task: to click on the Google AdSense ads on your website. They obliged and click on the AdSense ads on their computers at home, office and some corner in cyberspace and where not. Google can hear those clicks of yours or your relatives, friends, family members, neighbors and your other strange buddies.
4. Ads Autoclicker cheat
Next, you try ads autoclicker or clickbot / click-bots. These are specialized little program that can automatically "click" on the AdSense ads. Thus they are called click robot or click bot. The clickbot or autoclicker bot will scan your websites, triggered the clicking on the ads every few minutes. Advance autoclicker bot is also capable of cloaking the IP address to fool Google and make your website seems to be very popular worldwide. To cover the track, these clickbots or autoclicker bots will browse around the advertisers sites too while continuing its "clicks task".
5. Paid manual clickers cheat
If you think, auto clicker bots can be traced by Google, you try other option like paying $50 a month to professional AdSense clickers. These are groups of highly specialised Internet surfers with office in the dark rooms in streets corners in third-world countries such as China, India, Pakistan and Nigeria, helping AdSense account owners to earn good amounts of money before their AdSense account is disabled, that is. The professional clickers will browse around your websites, clicking on the ads every few minutes. Because they use human eyes, they know which ads worth more. And to be more convincing they can click a link or two, or sign up free offers or newsletters on the advertiser sites. Google can trace the pattern of the click as well as the origin of click and it won't be long before Google spot the footprint of cheat.
6. Click Rings cheat
Similar to hiring pro clicker, you can use your network. Network is power. Instead of working alone and pay pro clicker to do the job, you can join hands with those with similar objectives and distribute AdSense clicks among themselves. This is the AdSense Click Rings. Joining this click ring network means that your website address will be made known to members, who will regularly browse the website and click on your AdSense ads. In exchange, you will also do the same (return favour). The medium of communication used varies. Some click rings group used chat room, mail-list, bulletin boards or private forum, Yahoo groups as well as Instant Messaging (like MSN or Yahoo Messenger). A bit more complicated is the specialised AdSense exchange software for collecting members website address or URL and displaying other's websites for clicking. That's mean the member surfing or browsing to fellow members website is automatic and member just execute the last job, of clicking the AdSense ads.
7. Newsletter, eBook, ToolBar, browser extension cheat
If you have thousands of email address, you can include AdSense ads in your newsletters and send the newsletters to the subscribers. It is possible that you can get thousands of clicks from one newsletters. You can also create (or hire someone) a free-ware like toolbars, FireFox extension, screensavers or eBooks with your AdSense ads and distribute it free. This is a quick ways to get click but illegal. Google AdSense ads is suppose to be installed on a website not on other media or medium. Those clicks from newsletters, eBooks, screensaver can easily be detected by Google.
8. Visitor cheat (with manipulative words)
Placing words like "Please visit my sponsors" or "Check out the these ads" on your website is cheating. Not an all-out cheating but Google AdSense program policies only allowed text such as "Advertisements" or "Sponsored List". Google discourage you from luring or requesting your visitor to click on the ads because that would not be natural.
9. Spam cheat
This is the highest level all click-frauds, the Maestro of Fraudsters. She spams millions of emails regularly, offering to “satisfy your inner needs if you can help me check on the links on my website”. Of course, email is not the only way. What IRC and instant messaging (IM) are for, after all. She will look for unsuspecting victims, offering something too-good-to-be-true “if only they will visit the website and click on the links”.
10. Click-through-rate cheat
Whichever method(s) above used, there is one limiting condition: the CTR(click-though-rate). Any CTR that exceeds certain percentage (probably around 10%) will raise red flag in Google AdSense back room. To lower the CTR, the professional cheaters will create some pages on the same domain that attracts very high traffic. Some interesting freebies will sure do the tricks. AdSense code is pasted there, thus creating a very high page impressions. Whether or not the the ads are clicked does not matter anyway, because they are targeting low paying keyword that does not have much competition. The fake clicks are, of course, on where the big money is, the low traffic pages stuffed with high-paying keywords.