You say that orders are placed over the "Internet" which suggests that
neither the laptop user nor the provider of the destination server have
much control over the number nor type of "servers" that the IP traffic
might hop through between the client and the server.
But as an application provider you do have a say over whether an order
requires a VPN connection or not, and the IP address and physical location
of any VPN servers that may handle the I/O. Any VPN servers will most
likely have public IP addresses, and will assign private IP addresses to
VPN clients when they connect.
After you move your servers to one or more different data centers, the
question of whether the I/O passes through your office probably depends on
whether a server in your offices participates in the VPN interface.