Google Advertising ID is a unique identifier that allows mobile applications running on the Android operating system (OS) to gather data about specific customers in order to improve both personalization and customer analytics. An important goal of Google Advertising ID is to help advertisers target their ad buys in mobile app environments and reach potential customers in a cost-effective manner.
Google Advertising ID is part of the Google Play Services 4.0 release and will eventually replace Android ID. Google Advertising ID will allow users to opt out of the service and prevent their data from being collected. Google says this will give end users more control than they had under Android ID.
See also: customer intelligence