Accuracy of Realtor.com estimates

[Ricky Knack]

We all know a Z-estimate can vary wildly in either direction, but what has been your experience with how accurate the estimates are for properties on realtor.com? 

[Russell Brazil]

I dont even need to look at them to know they are not likely accurate.  2 identical houses from the outside right next to each other can have drastically different values based on whats inside those 4 walls. There is no way for an algorithm to know that.