Hi. Is there anyone out there know of any off the shelf pay per click tracking modules that i can use to integrate into my classified ads website. Basically, advertisers may put up as many ads as they wish, and are billed a micro charge for every click on their ads. something like 1 cent a click and this will be a flat rate... everyone pays only 1 cent a click. Is there anything out there that can be integrated into a php / mysql script?