Traders can be organized into groups, with each trader belonging to one or multiple groups. Trader groups let you segment traffic by niche. For example, if your site has both teen and mature content, you can create separate groups for each niche and direct traffic accordingly.
Use the group parameter in links to direct traffic to a specific group:
out.php?url=http://mature_gallery.com/&group=mature&p=50
This sends 50% of clicks to http://mature_gallery.com/ and 50% to other traders in the “mature” group.