I recently had a listing expire after three months on the market. Nothing has sold in my client's neighborhood for almost a year, so it wasn't a big surprise. We gave it a shot and it didn't work out for us. No biggie. She was prepared for the possibility and has no hard feelings toward me.
But that's not an accident. Despite our best efforts (by "our," I mean mine and my seller's joint efforts to prepare and present a great product to market). I don't make a big deal about it and I certainly don't lecture them or otherwise insult their intelligence; I just ask a simple question: "What will you do if the house doesn't sell?"
Then I shut up.
If the seller doesn't have to sell (and I'm happy to take those listings if they're reasonable on price), then I've planted the seed that I/we don't control the market and if the house doesn't sell, it might be beyond our/my control.
If the seller does need to sell, it forces them to think about the unthinkable -- that they'll own a house they don't want and can't afford. The next thing you know, they're asking me what they need to do to ensure that doesn't happen. Suddenly, I'M THE EXPERT and they'll listen to me!
It also works beautifully for sellers who want to test the market at their price. A similar approach: "What if the house doesn't sell at that price? Will you be okay with that" often works wonders in getting the seller to really think about what he's doing.
I don't consider myself a salesperson; I consider myself an advisor. Therefore, I don't try to convince my sellers that I can "sell" their homes. With the above words, I am relieved of the personal responsibility of selling a house that, for whatever reason, may not be sellable today.
For the record, my listings are always priced well, always staged and always easy to show. That's my job -- to help my seller prepare and present their home to market in the best possible light. That's all I can do.