Having worked with Phone Systems for call centers and financial services for more than a decade I found this very useful.

Interesting uses: You want to use sentiment analysis to automatically pinpoint calls with angry customers and bridge in a supervisor.

You want to detect the language of inbound messages to route them to a person who can respond quickly in native tongue.

You want to identify demographics of an inbound sales call so you can prioritize people with the best buying profile.

You want to use spam or fraud scoring on inbound calls and messages so you can drop them on the floor before they distract your staff.