Number employed in 2006: 395,000
Percent change in 2016: -9.9 percent
Education/training: Short-term on-the-job training and good phone and sales skills are all that are typically required.
2006 median salary: $24,190
Job outlook: Decline will come as a result of more people opting out of receiving sales calls from salespersons, and as call-blocking technology improves.