Click fraud is an intentional disruption of the pay per click advertising model with malice and forethought for competitive or financial gain.

Click fraud is often associated with unwanted or unqualified clicks but while unqualified visitors may not generate revenue, this activity may not constitute fraud in and of itself.

Left unchecked, fraudulent or erroneous clicks threaten to erode revenue generated from search listings and may ultimately call into question the credibility of search engine advertising.

While no one is certain of the exact size of click fraud in the search engine advertising world, we know it is responsible for perhaps hundreds of millions of dollars in advertiser losses each year.

Fraudulent click traffic can also be seen in much higher frequencies in highly competitive and popular search categories such as electronics, auto, finance and travel.

Next: Types of click fraud