When I buy a new house I'm not only interested in the price, but also in the estimated energy-bills. Would it be possible to add this kind of info to the placemarks?
What does it takes to make a self-filling datalayer? For example if you want to sell your house and it is relatively well insulated, you could add a placemark "$1500/year". If you get like 4 or 5 placemarks in a street you can verify if it is more or less correct. You can also add a placemark if you are just wondering what the rest of the streets pays. I think that this kind of data gets more important in the future of real-estate.