Placing ads strategically and effectively on a WordPress site requires effective management of the ads. Ad plugins for WordPress handle these management activities. Some WordPress themes provide ad management, but if you need more functionality, or your theme doesn’t have ad management features, consider an Ad Manager plugin. These plugins offer varying degrees of functionality Many of them allow you to display affiliate banners, sell advertising space, run Google AdSense, rotate ads, etc.
If you like making money from your WordPress site, you probably display some type of ads. And if you display ads on your WordPress site, an ad management plugin can make your life a lot simpler (and give you extra functionality that you wouldn’t be able to do manually).