To gain some visibility on your concurrent license usage, turn on Concurrent License Usage data collection from Administration > System > Licenses > Configure and Activate Licenses Use Report. Once this is active you will have an additional Metrics report option for Concurrent License Usage under Reports > Metrics.
The report offers a few options:
1) Report Type of Average or Maximum: Maximum means the highest number of licenses in use during a given period. For example, if the period is one hour then the maximum number of licenses that were actively in use during that hour may have been four, even though there may have been eight licenses or more available. Average would be the average number of concurrent licenses used during the selected time period.
2) Concurrent license type of Working or Logged In: FootPrints considers a concurrent license to be "working" if there was any concurrent license activity during the previous 1 hour. Logged In will include any agent that has not logged out or had been bumped out due to the time-out restriction.
In addition to the report, it is also possible to obtain additional concurrent license usage information from Administration > System > Logs > View System Logs > concurrent license usage log.
Regular analysis of these logs and reports can help you determine if the purchase of additional concurrent licenses is required based on demand.