It's not suprising that estimates based on "user-submitted data points" are not accurate. Everyone who ever tried to sell a house knows how difficult it is to

It's not suprising that estimates based on "user-submitted data points" are not accurate. Everyone who ever tried to sell a house knows how difficult it is to estimate real market price of property. Usually people will submit higher valuation of their house so that they can negotiate it down in case their valuation is not realistic. It is better to give higher value so that you have room for negotiation. Transaction prices will always differ from listing prices.