PA Server Monitor is licensed on a per-monitored-server/device basis. In other words, each server or device (meaning each unique IP address) to be monitored
requires a license.
One exception to the above: Any devices with only a Ping monitor attached are not counted towards the license. So you can ping as many devices as you want without using any licenses.
Subscription licenses are becoming quite popular for our IT service provider customers because there is no upfront cost, and the monthly cost can go up and down
with the number of clients you have. Support & Maintenance is already included in the cost of a Subscription License