Who Sees Ads is an advanced ad management plugin that lets you decide who will see your ads, for instance Adsense, depending on user defined conditions. You can manage ads in your templates (eg sidebar.php) or within posts and pages.
For instance, you could consider the following criteria: Is the visitor a regular reader? Does this visitor come from a search engine? Is the visitor currently reading an old post, or something fresh?
The plugin allows for easily creating display rules with a very advanced user interface.
For a more detailed documentation, demo of the interface, and examples of advanced usages of the plugin, please visit its official page: Who Sees Ads
Plugin doc: http://planetozh.com/blog/my-projects/wordpress-plugin-who-sees-ads-control-adsense-display/
Plugin dev: https://github.com/ozh/ozh-who-sees-ads
Features and pull requests: https://github.com/ozh/ozh-who-sees-ads
Tip: To keep track of this plugin’s evolution and features, you are advised to subscribe to the author’s feed