When you say that number is a 6% decline on all sales, do you mean that the average price is down 6% or that 6% fewer units were sold (compared to 1 YR ago). Regarding Zillow, I have a few friends on the West Coast who sold their places a few months ago, and they got almost exactly what Zillow had predicted. I don't know if there are any objective numbers on how well it does, though...