How Does Google AdSense Code Work?

What Is Google AdSense?

Google AdSense is an online advertising network that offers website owners the opportunity to make money by displaying advertising on their sites. Ads can appear on websites, blogs, search pages, RSS feeds, parked domains, videos and browser-based games. To become a publisher with Google AdSense, you'll need to fill out a short application and agree to follow the AdSense program policies. Google AdSense offers text and image ads in several sizes, fonts and colors. Upon approval by Google AdSense, you will be given a Publisher ID beginning with 'pub-' followed by 16 digits. Now, you will be able to log into your account and set up your advertising.

AdSense Code

Google AdSense creates the code, which the publisher copies and pastes into a web page or blog post at the point where it is to appear. This is an example of AdSense code for a 728-by-90-pixel ad. Google assigns the numbers following 'google_ad_client' and 'google_ad_slot.'

When a webpage containing this code is displayed, AdSense counts the page visit. If the visitor clicks on the ad, s/he is redirected to the advertiser's website, and Google counts the click and credits the AdSense publisher's account. Payments for clicks on ads range from a few cents to several dollars. There is no payment for the public-service ads, which are displayed when there is no paid advertising available.An AdSense publisher can log into Google AdSense at any time and see a running total of page views, clicks and earnings. More detailed reports are available for publishers of large websites with many ads.AdSense publishers may prevent competitors' ads from appearing, and may choose to review all advertising before it appears on the site.

Evolution of Google AdSense

In the past, Google also provided referral ads, which paid only if the visitor completed an action, such as purchasing a magazine subscription. AdSense referral advertising was discontinued in 2008. Google AdSense traditionally served up advertising relevant to the content of a web page. Beginning in March 2009, their policy changed to serving ads relevant to what a site visitor may be interested in, as revealed by cookies and browsing history. Both website owners and visitors may opt out of interest-based advertising.