“In iOS 7 and later, if you ask for the MAC address of an iOS device, the system returns the value 02:00:00:00:00:00. If you need to identify the device, use the identifierForVendor property of UIDevice instead. Apps that need an identifier for their own advertising purposes should consider using the advertisingIdentifier property of ASIdentifierManager instead.”
Apple is “essentially saying that you need to adopt IDFA for device identification,” noted Ryan Weber, co-founder and VP of product at NativeX, a company that works with developers and publishers to create native ads for apps. Even with ample warning from Apple that it was removing access to the UDID, some advertisers were “slow to respond,” Weber said. “In April, we saw 28% of publishers’ ad revenue on iOS was still coming from advertisers that supported the UDID for device identifier tracking, and by May [after Apple launched the new IDFA] that number dropped to 10%, but that remaining 10% needs to make the change.”
A smart move would be to support various types of tracking technologies, added Craig Palli, VP of business development at Fiksu, a mobile app marketing platform.
“As the choices for tracking technologies continue to evolve,” Palli said, “mobile app advertisers need to support multiple types of marketing attribution including the IDFA, digital fingerprinting and HTML5 rather than backing just one horse.”