Invalid click is a crime in internet for the program pay per click. In some case study the person intentionally click on ads without having actual interest in the target of the ad's link. In other case study, when a person, automated script, or computer program imitates a legitimate user of a web browser clicking on an ad, for the purpose of generating a charge per click. Invalid click is a type of controversy and increasing litigation.

Participate in PPC( Pay Per Click ) program for earn revenue from this website that is called as Publisher. But when webmaster (operators of web sites) display ads which indicate to click on advertising and the publisher believed that, this is valid web user clicks on an ad, the advertiser pays the advertising network, which in turn pays the publisher a share of this money.

1. Without the proper knowledge of such program when a person intentionally clicks on the ad for many times.
2. He being a familiar person to the publisher clicks on the ad but don’t show further interest on it.

But this whole process goes to click fraud / Invalid click when a person intentionally clicks on an ad in which he has not interest except gaining the money which is provided by the advertiser.

On other hand, a click fraud will occur when following reasons happen:

1. An automated script is being targeted to click the ad with or without the knowledge of the producer.
2. When somebody related to the producer or some content of the site influences the target customer to click on ad or gives him fake information which will lead him to click.

 This whole process goes to click fraud / Invalid click. In flowing examples help you understand non-contracting parties;

Competitors of advertisers: These parties may wish to harm a competitor who advertises in the same market by clicking on their ads.

Competitors of publishers: These persons may wish to frame a publisher. It is made to look like the publisher is clicking on its own ads. The advertising network may then terminate the relationship.

Other malicious intent: As with vandalism, there's an array of motives for wishing to cause harm to either an advertiser or a publisher, even by people who have nothing to gain financially.

Friends of the publisher: Sometimes upon learning a publisher profits from ads being clicked, a supporter of the publisher (like a fan, family member, or personal friend), will click on the ads to help.