This is like exchanging links but on a different higher level. This may cost a bit more than exchanging or trading links but could be made cheaper because you get to earn credits. You can use those credits when viewing others traffic, while you earn credits when someone views yours.
Traffic exchange services are the viewing of another’s site or page. This is done vice versa where a site can use your sites contents and so can you to his or her site. You both benefit from each others efforts to generate traffic. The other sites visitors can go to your pages and know more about your site as well as theirs. Once again the public awareness of your sites existence is boosted.