I used to use one in my previous job. It's still used by my former coworkers.

We had an on call rotation and found that handing off the pager was the easiest, cheapest means to manage it. Each week one member of our team kept the pager. At the end of their on-call week they'd pass it to the next person.

We looked into having a phone number that would forward to our cell phones and several other options, but this was the least complicated method, and it seemed to work pretty well.

The trick was finding one of the old style pagers that wasn't enormous. All the pagers sold now are big to support a large display and text paging capabilities. We only needed numeric paging capabilities but only ever managed to find one numeric pager, which eventually developed a bad LCD.