Even as Google has opted to start using mobile handset “unique device identifiers” (UDIDs) in its mobile advertising efforts, the company will simultaneously roll out new privacy controls and add the ability for users to opt-out of UDID tracking, Search Engine Land reports. Most other mobile ad networks have been using UDID tracking for some time, prompting a grand jury investigation and calls for legislation to protect personally-identifiable consumer information from being misused.
Google argues that UDID tracking is useful for features such as frequency capping (limiting the number of times the same ad is sent to a device), behavioral targeting and better conversion tracking (finding out how often users of a particular device respond to ads). It has chosen to make it easier for users to opt-out of what it calls “more precise ad targeting” and turn off the UDID feature, but this will not affect the number of ads users see — only how well-matched those ads are to what Google perceives based on other information (what web sites are visited, searches performed and so on) are the user’s specific interests.
Other mobile ad networks like JumpTap already offer UDID opt-out, and while Apple’s iAd network does not use UDID tracking, it does use location-based tracking (with an option to opt-out) on devices running iOS 4 or higher.
Google’s plan for ensuring privacy while using UDID tracking involves “double-anonymization” of the device identifier by hashing the info before it is sent to Google’s servers, where it is then mapped to an anonymous ID. The company will also notify users that their device is being tracked via in-app ads running via AdSense and AdMob networks, and update the controls in the iOS and Android versions of the Google search app to make it easy for users to find and adjust their privacy settings, including the UDID tracking opt-out
