I have noticed that despite the claims that banners have been a decrease in marketing, I still noticed they are still quite popular. I am an advertising manager of a web-site who wants to sell contextual and banner advertising : www.citycatalogue.com . My question is: How can people who post there banners on different sites, know where there traffic came from, what kind of traffic is it ( sources) and, can they determine the demographics and other things , by implementing this in the code of there banner? and is this possible at all? Also I am curious does anyone on this forum sell advertising on there web-site and can reccomend or suggest me some things on how its done best? Please let me know. I am webmaster and I am curious if people can see where the traffic is coming from which i am generating on my site.