It's funny, my neighborhood has a great relationship with a couple local dedicated Agents, we've all been concerned about the housing prices, our tax assessments and even more importantly, the low estimates Zillow keeps showing in our neighborhood (compared with every other source of assessments)...they both agreed that pretty much nobody in the industry in our area even pays attention to Zillow anymore the estimates are so far off the actual value.

edit just checked, my house for example, sits on the same block as two recent home sales, neither one is reflected in Zillow and both sold for far higher than the "Zestimate". The townhouses a few blocks over (which originally sold for about 70% of my home's price and are about half the size) are full of recent sales that are within 10-20% of the "Zestimate". The much smaller single home facing mine is "Zestimated" at a few tens of thousands higher than mine, but sold originally for 80% of my home's price.

It's basically nonsensical.