Customers and management will appreciate the proactive nature of Darknets, meaning you can "spot bot" and other malware before it is used for spam or DDoS.
You could readily host IDS boxes in your Darknet, thus matching on the known fingerprints.
Best of all you can use your Darknet deployment and data to convince others to do the same. Darknets aren't just for providers. They will fit nicely in enterprise and (supposedly) disconnected networks.