Thanks in advance,
Shabir
Unique Physical IP is the actual IP of the machine. In some cases, a public IP can be assigned to a gateway that in turn can point to a range of physical IPs on an internal network. Physical IPs can be part of an external or internal network. This would include all IP ranges set aside for inernal networks (ie. 10.#*$!.xxx.xxx or 192.168.xxx.xxx)
Unique Public IP. Is an actual IP that can be accessed by the public. This would include all IPs except for the 10.xxx.xxx.xxx or 192.168.xxx.xxx which are reserved for internal networks.
But that would be odd, as the MAC address is seen only by the local switching equipment.
I would ask them what they mean by each of those options. If you can get a bit more detailed for us, we'll help you with the SEO benefits of each.