Zillow - give me a pillow

Zillow.com still is not accurate with house prices based on my scientific and highly biased survey by myself of my house. About an 18% below market valuation of a simple track house in Menlo Park, CA. What would I have said if the valuation was 18% higher than what I thought the value was? Maybe not blogged this issue. Like I said, it was a very biased survey. I hope nobody makes buying decisions based on Zillow. I sure won't list my house based on Zillow!