Apple has introduced and turned on tracking by default for advertising purposes in iOS 6 ( identifierForAdvertising [IDFA] which is am cross-app/publisher identifier and identifierForVendor [IDFV] which is a publisher-specific identifier). Feel disturbed with these new tracking technologies provided along with iOS 6?! Here is how you can disable them on your iPod, iPad or iPhone.
Open settings menu -> open up the “General” settings -> then, select “About”.
Select “Advertising”.
In order to stop tracking, you need to set “Limit Ad tracking” to “on”.
Now your iDevice is safe from advertisement tracking!