True, but the pressure on the company to pay high commissions is much more than for a typical employee. And unlike an employee's work, their total compensation

True, but the pressure on the company to pay high commissions is much more than for a typical employee. And unlike an employee's work, their total compensation is much more correlated with performance. I can work like crazy and not have an idea on whether I'll get a bonus, and if I do, how much. And I still have to work regular hours. Someone in sales has a much clearer idea how much extra he can make and how to get there. And it's a common occurrence that a top performer simply takes it easy for a few weeks (e.g. not come in to the office or work only 3 hours per day) as they made so much money after a big win. Their hours are a lot more flexible. Of course, most are not top performers and do end up working long hours.