How secure is your job in radio?

As the celebrations surrounding Austereo veteran Lee Simon for reaching 40 years in radio last week rivaled that afforded a winning contestant on Survivor, it occurred to me that such a milestone may be more difficult to achieve in radio than in many other industries. Apart from careers such as rodeo clown or suicide bomber, most other jobs in, say, banking, health care or teaching seem far more stable than those in radio. Do you feel that way? Or are you relatively comfortable with the level of job security that Radio provides?

Either way, is radio different to other industries? Why do people leave radio? Are they more often pushed than choose to leave of their own accord?