When you employ a real estate professional to sell your house for you think about it like this.
The agent and agency are performance based.
Your agent will not be paid for their service untill the property is sold.
The only investment you need to make is on professional marketing.
So why would you worry about selling privately when you have to worry about all the fuss when you can get an agent to work for you doing the long hard tasks and giving you great advice for free.
This is the great thing about it.