When I was in the mortgage biz, I used zillow and abc's of real estate (similar sites) and there are others also. As far as the homes go, in some cases the value and the data are almost correct, but in others they are not even close. I used it as a way to determine if the value of a client's home was possible, given the location. I know, in my case, zillow matches up pretty closely with county records. As you all probably know, the county does not come into your home when they appraise properties. They take their best guess from the outside, as to what is inside. They guessed at mine to be 3 bdrm and 1 bath. I actually have 3 bdrm, 2 full bath, and 2 half baths. They have my entire neighborhood incorrect, and obviously had the same appraiser that did the entire neighborhood. These sites have very little value as far as giving an accurate idea of what your home's size, or number of rooms, or value is. The only accuracies on these sites are the values of the homes that sold closeby, however most of the data they use is outdated, thus even those prices, although at one time correct, no longer are accurate either.