The opt out process works by setting a cookie with value OPTOUT, and replacing your user ID, if there was any. This way, every time you browse web sites with ads served by e-planning, your browser will send the OPTOUT value to e-planning, indicating that you do not wish to be identified or tracked. If you delete cookies from your browser, you will have to carry out the opt out process again. If you use more than one browser in your computer, you must perform the opt out process once for each browser. Moreover, it is necessary that your browser accepts third party cookies in order for the opt out process to work.
In this page you can opt out from e-planning cookie tracking.