What is AdSense?
AdSense is an advertising program that lets non-Google websites
participate in the AdWords advertising network. To understand AdSense,
then, you have to first understand AdWords.
AdWords is a self-service advertising program
for placing ads on Google's search result pages and on partner sites.
Anyone with a credit card can sign
up for AdWords and have their ads shown on Google almost immediately.
Most AdWords ads are shown on Google's search result pages,
where they are called "Sponsored Links". So far, only text ads
have been shown on the result pages. A text ad consists of a
title up to 25 characters long, two description lines (up to 35
characters each), and a domain name or partial URL (up to 35
characters as well). Advertisers pay when a Google searcher
clicks the title or URL of an ad and are redirected to the
advertiser's landing page. This is known as cost-per-click
or CPC for short.
The text ads shown on a result
page are selected using an algorithm that factors in price
(how much the advertiser is willing to pay per click),
clickthrough rate (how well the ad is performing),
keyword relevance, and other factors.
AdWords also offers image and video ads, but these are shown
on partner sites, not on the search pages. These ads are bought
on a cost-per-thousand impressions or CPM basis.
AdSense extends AdWords to third-party (non-Google)
partner sites. Sites that meet certain
basic criteria can elect to display AdWords ads (text, image
or video formats) on their pages. Collectively, AdSense sites
are part of the Google content network.
Ad delivery to AdSense sites is completely automated and is
done on a per-page basis by analyzing the content of the page
using a patented algorithm and selecting the ads that best
match the content. This is called contextual targeting
and is the primary reason for AdSense's success:
relevant advertisements have much higher click-through rates
than random image ads. They're also incredibly easy to add
AdSense publishers (site owners) are paid a percentage
of the ad revenues earned by Google from clicks and impressions
on that publisher's sites. The exact percentage has
not been disclosed. Payments are made on a monthly basis
by cheque or by electronic money transfer.
Comments or questions about this AdSense FAQ entry?
Leave them on the
AdSense FAQ for discussion.