setting cookie from subdomain that includes main domain for google analytics

Question

Main site - www.example.com
App site - app.example.com

The cookie is created on app.example.com, but should also work for www.example.com.

setcookie("gacookie", time(), time()+31536000, '/');

Is this possible? What would be the code?

The cookie is being used to create a filter for GA that will exclude all current members of my application. The cookie is set the first time they log in. Both the main domain and the subdomain use the same GA tracking code.

Also, if another site that I visit has a cookie with the string "gacookie", will that effect the Google Analytics filter, or will it only ready cookies from the domain and subdomain it is tracking...

Answer 1

Here are more details on how to integrate tracking across sub/domains.

http://code.google.com/apis/analytics/docs/tracking/gaTrackingSite.html