Calling legislators to encourage support for pending legislation. Calling the doctor's office for test results. Calling the IRS for questions about tax returns. Calling a lawyer to discuss legal matters. Eliminates relying on friends, co-workers, or family, to make calls.
Students can call other students to go over homework.
Consumers can make credit card purchases from catalogs, stores, etc. A technician calls the office to check on parts availability. A contractor calls clients before going to the job site, avoiding wasted trips. Professionals can confer with other professionals. A teacher needs to advise the deaf parents of their child's performance.