I'm facing a big problem with my low cost tablets from China. Serial number is the same, device id from telephony is the same and now I discover that also Settings.Secure.ANDROID_ID is the same on each device.
How Settings.Secure.ANDROID_ID is generated?
You can read this here http://developer.android.com/reference/android/provider/Settings.Secure.html#ANDROID_ID
Android ID: A 64-bit number (as a hex string) that is randomly generated on the device's first boot and should remain constant for the lifetime of the device. (The value may change if a factory reset is performed on the device.)
But on the Androids Developers Blog they write about your problem and show you a solution. http://android-developers.blogspot.in/2011/03/identifying-app-installations.html
ANDROID_ID seems a good choice for a unique device identifier. There are downsides: First, it is not 100% reliable on releases of Android prior to 2.2 (“Froyo”). Also, there has been at least one widely-observed bug in a popular handset from a major manufacturer, where every instance has the same ANDROID_ID.
