AdSense is an ad serving application run by Google Inc. Website owners can enroll in this program to enable text, image, and video advertisements on their websites. These advertisements are administered by Google and generate revenue on either a per-click or per-impression basis. Google beta tested a cost-per-action service, but discontinued it in October 2008 in favor of a DoubleClick offering (also owned by Google).In Q1 2010, Google earned US$2.04 billion ($8.16 billion annualized), or 30% of total revenue, through AdSense.
Google uses its Internet search technology to serve advertisements based on website content, the user's geographical location, and other factors. Those wanting to advertise with Google's targeted advertisement system may enroll through AdWords. AdSense has become a popular method of placing advertising on a website because the advertisements are less intrusive than most banners, and the content of the advertisements is often relevant to the website.
Many websites use AdSense to monetize their content; it is the most popular advertising network
. AdSense has been particularly important for delivering advertising revenue to small websites that do not have the resources for developing advertising sales programs and sales people. To fill a website with advertisements that are relevant to the topics discussed, webmasters implement a brief script on the websites' pages. Websites that are content-rich have been very successful with this advertising program, as noted in a number of publisher case studies on the AdSense website.Some webmasters invest significant effort into maximizing their own AdSense income. They do this in three ways:
- They use a wide range of traffic-generating techniques, including but not limited to online advertising.
- They build valuable content on their websites that attracts AdSense advertisements, which pay out the most when they are clicked.
- They use text content on their websites that encourages visitors to click on advertisements. Note that Google prohibits webmasters from using phrases like "Click on my AdSense ads" to increase click rates. The phrases accepted are "Sponsored Links" and "Advertisements".
The source of all AdSense income is the AdWords program, which in turn has a complex pricing model based on a Vickrey.AdSense commands an advertiser to submit a sealed bid (i.e., a bid not observable by competitors). Additionally, for any given click received, advertisers only pay one bid increment above the second-highest bid. Google currently shares 68% of revenues generated by AdSense with content network partners.
Types
Adsense for Feed
In May 2005, Google announced a limited-participation beta version of AdSense for Feeds, a version of AdSense that runs on RSS and Atom feeds that have more than 100 active subscribers. According to the Official Google Blog, "advertisers have their ads placed in the most appropriate feed articles; publishers are paid for their original content; readers see relevant advertising—and in the long run, more quality feeds to choose from."
AdSense for Feeds works by inserting images into a feed. When the image is displayed by a RSS reader or Web browser, Google writes the advertising content into the image that it returns. The advertisement content is chosen based on the content of the feed surrounding the image. When the user clicks the image, he or she is redirected to the advertiser's website in the same way as regular AdSense advertisements.
AdSense for Feeds remained in its beta state until August 15, 2008, when it became available to all AdSense users.
For Search
A companion to the regular AdSense program, AdSense for search, allows website owners to place Google search boxes on their websites. When a user searches the Internet or the website with the search box, Google shares 51% of the advertising revenue it makes from those searches with the website ownerHowever the publisher is paid only if the advertisements on the page are clicked; AdSense does not pay publishers for mere searches.
For Domain and Video
Adsense for domains allows advertisements to be placed on domain names that have not been developed. This offers domain name owners a way to monetize domain names that are otherwise dormant. Adsense for domains is currently being offered to some users, with plans to make it available to all in stages.
On December 12, 2008, TechCrunch reported that AdSense for Domains is available for all US publishers.
AdSense for video allows publishers with video content to generate revenue using ad placements from Google's extensive Advertising network including popular Youtube videos.
How it Works
The webmaster inserts the AdSense JavaScript code into a webpage.Each time this page is visited, the JavaScript code uses inlined JSON to display content fetched from Google's servers.For contextual advertisements, Google's servers use a cache of the page to determine a set of high-value keywords. If keywords have been cached already, advertisements are served for those keywords based on the AdWords bidding system. (More details are described in the AdSense patent.)For site-targeted advertisements, the advertiser chooses the page(s) on which to display advertisements, and pays based on cost per mille (CPM), or the price advertisers choose to pay for every thousand advertisements displayedFor referrals, Google adds money to the advertiser's account when visitors either download the referred software or subscribe to the referred service. The referral program was retired in August 2008.
Search advertisements are added to the list of results after the visitor performs a search.
Because the JavaScript is sent to the Web browser when the page is requested, it is possible for other website owners to copy the JavaScript code into their own webpages. To protect against this type of fraud, AdSense customers can specify the pages on which advertisements should be shown. AdSense then ignores clicks from pages other than those specified.
Criticism
Due to alleged concerns about click fraud, Google AdSense has been criticized by some search engine optimization firms as a large source of what Google calls "invalid clicks", in which one company clicks on a rival's search engine advertisements to drive up the other company's costs.To help prevent click fraud, AdSense publishers can choose from a number of click-tracking programs.
These programs display detailed information about the visitors who click on the AdSense advertisements. Publishers can use this to determine whether or not they have been a victim of click fraud. There are a number of commercial tracking scripts available for purchase.
The payment terms for webmasters have also been justly criticized
Google withholds payment until an account reaches US$100but many micro content providers
require a long time—years in some cases—to build up this much AdSense revenue. However, Google will pay all earned revenue greater than US$10 when an AdSense account is closed and not disabled.
Many website owners complain that their AdSense accounts have been disabled just before they were supposed to receive their first paycheck from Google. Google claims accounts have been disabled due to click fraud or forbidden content, but have offered no proof of this. An automated email is sent to the publisher's owner which offers no reasoning, or options but a link to file an appeal. In the email, Google states that "Because we have a responsibility to protect our AdWords advertisers from inflated costs due to invalid activity, we've found it necessary to disable your AdSense account. Your outstanding balance and Google's share of the revenue will both be fully refunded back to the affected advertisers." The revenue generated whether legitimate or not is taken.
Google came under fire when the official Google AdSense Blog showcased the French video website Imineo.com. This website violated Google's AdSense Program Policies by displaying AdSense alongside sexually explicit material. Typically, websites displaying AdSense have been banned from showing such content.Some sites have been banned for distributing copyrighted material even when they hold the copyright themselves or are authorized by the copyright holder to distribute the material.It has been reported that using both AdSense and AdWords may cause a website to pay Google a commission when the website advertises itself.Insome cases, AdSense displays inappropriate or offensive ads. For example, in a news story about a terrorist attack in India, an advert was generated for a (presumably non-existent) educational qualification in terrorism.AdSense sets tracking cookies that are viewed by someas important threat for the privacy. Webmasters that use AdSense must place the appropriate warning in the privacy policy page.
