Sorry for the long title for the thread... I came across an article a long time ago about a PPC network that works as follows: - A person visits your site (cookie tracked). - On websites associated with the PPC network (mostly news related sites) a banner ad for the website will display [constantly reminding the viewer of the website they visited - being very targeted] Basically, banner ads only appear to previous website viewers and a PPC fee is only applied when the banner is clicked (no additional costs for the service). I can't remember the PPC network name but I'm sure there are heaps of them out there now that do the above. Appreciate some references from those who know.