1. A system for monitoring information technology assets of enterprises, the system comprising: an application service provider database configured: to receive performance data from a plurality of Simple Network Management Protocol (SNMP)-enabled devices of a plurality of enterprises on a by-enterprise basis responsive to a request from a polling proxy server, wherein: the received performance data describes performance of the plurality of SNMP-enabled devices and includes application usage data, device metrics, and Internet Service Provider (ISP) performance data across data, wireless, voice over Internet Protocol, and virtual private networks (VPNs) for the plurality of SNMP-enabled devices of the plurality of enterprises; and the polling proxy server is communicatively coupled with polling servers that perform functions of SNMP data gathering, the polling servers communicatively coupled with the polling proxy server to determine SNMP-enabled devices that need to be polled, the polling servers grouped into polling clusters, wherein each polling cluster has at least two polling servers that enable each enterprise to use a same Internet Protocol (IP) address range for associated SNMP-enabled devices, and that enable unique identification of SNMP-enabled devices, each polling cluster assigned to a virtual firewall system; and to receive an alert about a prediction of a failure of an SNMP-enabled device from the polling proxy server; and a user interface to the application service provider database configured: to display a report showing a correlation of the received performance data and costs associated with SNMP-enabled device performance described by the received performance data for a respective enterprise responsive to receiving an authorized request from the respective enterprise, wherein costs associated with SNMP-enabled device performance comprise an unrealized cost; and to provide a correlation of virtual private network tunnel sessions across heterogeneous network environments.