The redirection file is a file that you create. It usually includes script to parse the query string sent by the AdRotator object and redirect the user to the URL associated with the advertisement that they clicked on.
You can also include script in the Redirection file to count the number of users that have clicked on a particular advertisement, and save this information to a file on the server.
The following example redirects the user to the advertiser's home page.
---ADREDIR.ASP--- <% Response.Redirect(Request.QueryString("url")) %>