u should have asked this b4, so no more time wasrting in searching the answers.,
its called traffic trading script.,
http://www.scriptpulse.com/
there are many free and paid script out there.,
for free script ,script owner takes 1-2% of ur traffic to their choice of site .,
paid scripts are from 80-250 bucks per license.,
after installation and setting up script on ur site
u have to find another sites, using traffic trading script in ur niche, and register their for traffic trading.
the % traffic u send is called skimming, 60% is normal.