I'd like to pose this question to anyone who has insight into the 'off-market' market.

Why on Earth would anyone not use a real estate agent to sell their house?

It reminds me of the people who attempt to perform medical procedures on themselves or try to rebuild an engine in their driveway.

With anything in life I'm sure there's an element of 'it takes all kinds' but do you find a common theme among the market of those who do not work with an agent?

Is it ignorance?  

A stubbornness of not wanting to pay a (usually well deserved) commission? 

Circumstances?  (e.g. needing to sell in a few days)

Apathy?

It'd be interesting to hear what you've all experienced.