Click fraud is a type of ad fraud that occurs on the Internet in pay-per-click (PPC) online advertising. In this type of advertising, the owners of websites that post the ads are paid based on how many site visitors click on the ads. Fraud occurs when a person, automated script, computer program, or an auto clicker imitates a legitimate user of a web browser, clicking on such an ad without having an actual interest in the target of the ad's link to increase revenue. Click fraud is the subject of some controversy and increasing litigation due to the advertising networks being a key beneficiary of the fraud.
Media entrepreneur and journalist John Battelle describes click fraud as the intentionally malicious, "decidedly black hat" practice of publishers gaming paid search advertising by employing robots or low-wage workers to click on ads on their sites repeatedly, thereby generating money to be paid by the advertiser to the publisher and to any agent the advertiser may be using.
Pay-per-click advertising
PPC advertising is an arrangement in which webmasters (operators of websites), acting as publishers, display clickable links from advertisers in exchange for a charge per click. As this industry evolved, a number of advertising networks developed, which acted as middlemen between these two groups (publishers and advertisers). Each time a (believed to be) valid Web user clicks on an ad, the advertiser pays the advertising network, which in turn pays the publisher a share of this money. This revenue-sharing system is seen as an incentive for click fraud.
The largest of the advertising networks, Google's AdWords/AdSense and Yahoo! Search Marketing, act in a dual role, since they are also publishers themselves (on their search engines). According to critics, this complex relationship may create a conflict of interest. This is because these companies lose money to undetected click fraud when paying out to the publisher but make more money when collecting fees from the advertiser. Because of the spread between what they collect and pay out, unfettered click fraud would create short-term profits for these companies.
Non-contracting parties
A secondary source of click fraud is non-contracting parties, who are not part of any pay-per-click agreement. This type of fraud is even harder to police because perpetrators generally cannot be sued for breach of contract or charged criminally with fraud. Examples of non-contracting parties are: Competitors of advertisers: These parties may wish to harm a competitor who advertises in the same market by clicking on their ads. The perpetrators do not profit directly but force the advertiser to pay for irrelevant clicks, thus weakening or eliminating a source of competition. Competitors of publishers: These persons may wish to frame a publisher. It is made to look as if the publisher is clicking on its own ads. The advertising network may then terminate the relationship. Many publishers rely exclusively on revenue from advertising and could be put out of business by such an attack. Other malicious intent: As with vandalism, there are many motives for wishing to cause harm to either an advertiser or a publisher, even among people who have nothing to gain financially. Motives include political and personal vendettas. These cases are often the hardest to deal with, since it is difficult to track down the culprit, and if found, there may be little legal action that can be taken against them. Friends of the publisher: Sometimes upon learning a publisher profits from ads being clicked, a supporter of the publisher (like a fan, family member, political party supporter, charity patron or personal friend) will click on the ads to help. This can be considered patronage. However, this can backfire when the publisher (not the friend) is accused of click fraud.
Advertising networks may try to stop fraud by all parties but often do not know which clicks are legitimate. Unlike fraud committed by the publisher, it is difficult to know who should pay when past click fraud is found. Publishers resent having to pay refunds for something that is not their fault. However, advertisers are adamant that they should not have to pay for phony clicks.
Organization Click fraud can be as simple as one person starting a small website, becoming a publisher of ads, and clicking on those ads to generate revenue. Often the number of clicks and their value are so small that the fraud goes undetected. Publishers may claim that small amounts of such clicking are an accident, which is often the case.
Much larger-scale fraud also occurs in cybercrime communities.Schonfeld, Erick; The Evolution Of Click Fraud: Massive Chinese Operation DormRing1 Uncovered". TechCrunch. October 8, 2009. According to Jean-Loup Richet, Professor at the Sorbonne Business School, click fraud is frequently one link in the large ad fraud chain and can be leveraged as part of a larger identity fraud and/or attribution fraud. Those engaged in large-scale fraud will often run scripts which simulate a human clicking on ads in Web pages. However, huge numbers of clicks appearing to come from just one, or a small number of computers, or a single geographic area, look highly suspicious to the advertising network and advertisers. Clicks coming from a computer known to be that of a publisher also look suspicious to those watching for click fraud. A person attempting large-scale fraud from one computer stands a good chance of being caught.
One type of fraud that circumvents detection based on IP patterns uses existing user traffic, turning this into clicks or impressions.Gandhi, Mona; Jakobsson, Markus; Ratkiewicz, Jacob;Badvertisements: Stealthy Click-Fraud with Unwitting Accessories ", APWG eFraud conference, 2006 Such an attack can be camouflaged from users by using 0-size iframes to display advertisements that are programmatically retrieved using JavaScript. It could also be camouflaged from advertisers and portals by ensuring that so-called "reverse spiders" are presented with a legitimate page, while human visitors are presented with a page that commits click fraud. The use of 0-size iframes and other techniques involving human visitors may also be combined with the use of incentivized traffic, where members of "Paid to Read" (PTR) sites are paid small amounts of money (often a fraction of a cent) to visit a website and/or click on keywords and search results, sometimes hundreds or thousands of times every day Some owners of PTR sites are members of PPC engines and may send many email ads to users who do search, while sending few ads to those who do not. They do this mainly because the charge per click on search results is often the only source of revenue for the site. This is known as forced searching, a practice that is frowned upon in the Get Paid To industry.
Organized crime can handle this by having many computers with their own Internet connections in different geographic locations. Often, scripts fail to mimic true human behavior, so organized crime networks use Trojan code to turn the average person's machines into zombie computers and use sporadic redirects or DNS cache poisoning to turn the oblivious user's actions into actions generating revenue for the scammer. It can be difficult for advertisers, advertising networks, and authorities to pursue cases against networks of people spread around multiple countries.
Impression fraud is when falsely generated ad impressions affect an advertiser's account. In the case of click-through-rate-based auction models, the advertiser may be penalized for having an unacceptably low click-through for a given keyword. This involves making numerous searches for a keyword without clicking the ad. Such ads are disabled automatically, enabling a competitor's lower-bid ad for the same keyword to continue, while several high bidders (on the first page of the search results) have been eliminated.
Hit inflation attack A hit inflation attack is a kind of fraudulent method used by some advertising publishers to earn unjustified revenue from the traffic they drive to the advertisers' Web sites. It is more sophisticated and harder to detect than a simple inflation attack.
This process involves the collaboration of two counterparts: a dishonest publisher, P, and a dishonest website, S. Web pages on S contain a script that redirects the customer to P's Web site, and this process is hidden from the customer. So, when a user U retrieves a page on S, it would simulate a click or request to a page on P's site. P's site has two kinds of webpages: a manipulated version and an original version. The manipulated version simulates a click or request to the advertisement, causing P to be credited for the click-through. P selectively determines whether to load the manipulated (and thus fraudulent) script to U's browser by checking if it was from S. This can be done through the Referrer field, which specifies the site from which the link to P was obtained. All requests from S will be loaded with the manipulated script, and thus the automatic and hidden request will be sent.
This attack will silently convert every innocent visit to S to a click on the advertisement on P's page. Even worse, P can be in collaboration with several dishonest websites, each of which can be in collaboration with several dishonest publishers. If the advertisement commissioner visits the Web site of P, the non-fraudulent page will be displayed, and thus P cannot be accused of being fraudulent. Without a reason for suspecting that such collaboration exists, the advertisement commissioner has to inspect all the Internet sites to detect such attacks, which is infeasible.
Another proposed method for detection of this type of fraud is the use of association rules. An extended version appeared in a University of California, Santa Barbara, Department of Computer Science, technical report 2005-23.
Manipulation of organic search results One major factor that affects the ranking of websites in organic search results is the CTR (click-through rate). This is the ratio of clicks to impressions, or in other words how many times a search result is clicked on compared to the number of times the listing appears in search results.
In contrast to PPC fraud, where a competitor leverages the services of a botnet or low-cost labour to generate false clicks, in this case the objective is to adopt a "beggar thy neighbour" policy against competitors by making their CTR rate as low as possible, thereby diminishing their position in search results.
Bad actors will therefore generate false clicks on organic search results that they wish to promote, while avoiding search results they wish to demote. This technique can effectively create a cartel of business services controlled by the same bad actor, or it can be used to promote a certain political opinion etc. The scale of this issue is unknown, but is certainly evident to many website developers who pay close attention to the statistics in webmaster tools.
Legal cases
Lawsuits Disputes over the issue have resulted in a number of lawsuits. In one case, Google (acting as both an advertiser and advertising network) won a lawsuit against a Texas company called Auction Experts (acting as a publisher), which Google accused of paying people to click on ads that appeared on Auction Experts' site, costing advertisers $50,000. Despite the networks' efforts to stop it, publishers are suspicious of the motives of the advertising networks because the advertising network receives money for each click, even if it is fraudulent.