Brandon,
Your assumption about inferred information coming from the IP address is correct. An IP can indicate host country and possibly a company domain if the network is private and that company owns and publishes ownership of an IP address(s).
It's the same information you would receive if you did a look-up on an IP address.
The cookie lets Munchkin know if they are returning visitors (along with other data if we have been given any).
Hope this makes sense.
Thanks,
James