Stress
The stress can vary. Like any sales job, there's always a gnawing feeling of back pressure pushing you to sell—if you don't, you don't get paid. And because you're sometimes only looking for two yearly placements to pull even, three to pull ahead, four to have a great year, five to be rolling in it…the stakes for any one job are huge.
On the other hand, you only need to make two sales per year to pull even. And that's a pretty small number. You could make two sales in your sleep.