e-bannerx.com utilizes its original Target Groups concept for effective Campaign and Banner targeting:

You shape certain target audience (group of Visitors) by creating special Target Group and then apply this Target Group to different Campaigns and Banners, and the Banners are displayed to Visitors from this Target Group.

Example:

You can shape the following sophisticated Target Group for your product: USA citizens, who are interested in Business and Economy, who surf the Web during business hours on business days, using AOL Internet service.

If you wish, Target Groups can be simpler, for example:

"English-speaking people interested in computer games."