
Google touts the updated AdSense's "more insight, more efficiency and greater control" as reasons to upgrade.
AdSense is Google's interface for publishers that places Google's ads on websites and, in turn, generates revenue on either a per-click or per-impression basis.
Google picked up AdSense in 2003 when it bought Applied Semantics for just over $100 million.
How AdSense works (from Wikipedia)
- 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 displayed.
- 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.