A visitor using multiple devices
When the same visitor uses different devices, without being identified through a Campaign or custom ID, anonymous profiles are created for the different devices. One and the same visitor will have in that case multiple anonymous profiles for the different devices. When that visitor is identified on device A, his anonymous profile for device A will be merged with the new identified profile. But on device B he will still only have his anonymous profile for that device, until he identifies himself (through email or login on page) and his anonymous profile for device B will be merged with his identified profile. This means that multiple anonymous profiles can be merged with one and the same identified profile.