Without monitoring, you discover problems when users call to complain. By then, the damage is done.
Monitoring gives you:
Proactive detection. Find failing links before they drop.
Faster troubleshooting. When something breaks, metrics tell you what changed.
Capacity planning. Trends show when you need more bandwidth.
Accountability. SLAs require proof. Monitoring data shows you met your targets.
The cost of monitoring is a fraction of the cost of outages. Every minute of downtime has a price tag.