The Corson Residential Report

A recent blog in the Baltimore Sun revealed some of the pitfalls of using Zillow.com to estimate the value of your home.  Yes, I know it is a self-serving article, but it does not make it any less true.  If accuracy does not matter and you just want a "quick and dirty" estimate of value, go right ahead. If you need an estimate to make a buying, selling, investing, lending decision, get a professional.  If you need to know what the property is worth because you are the personal representative of an estate or if you are involved in some legal matter such as divorce, bankruptcy or a dissolution of a partnership, Zillow.com is not going to be satisfactory.  There is no substitute for an experienced appraiser you trust to get an unbiased, supportable, and reliable estimate of value.  An accurate appraisal with detailed market analysis will cost you about $400.  What will an inaccurate and unreliable computer generated valuation cost?

http://weblogs.baltimoresun.com/business/realestate/blog/2010/02/zillows_homevalue_estimates_criticized.html