One of the advantages of IP is its ability to simply add on cameras by plugging into any network connection.
When scaling an IP camera system to an enterprise level there is a requirement for substantial managed networking equipment and significant bandwidth.

Analog cameras can be virtually expanded as there is no requirement for bandwidth or data transmission between the cameras and the recorders. Since analog cameras do not require bandwidth they can exponentially scale with minimal network concerns as they are plugged directly into the DVR bypassing network transmission.