Is it possible to serve ads only to visitors from certain US states? Can this be accomplished with php?
Yep... you would need a geotargetting database (For one down to the state level, I don't know of any free ones). For this tool I use the IP 2 Location database. With that you can determine the state (or even city) the user is in based on their IP address.
Thanks for the info Shwan! How difficult would it be to design the db to display ads to all states except a couple? Do you have pay for the DB every year? Joshua