From David Friedman's Blog
My presumption is that the reason we don't see this is because it isn't efficient. It is costly to set up a mechanism that would raise and lower enough windows in a house to really effect the temperature. Even if we eventually see something like this in new houses, that wouldn't mean that it was efficient to put the system in older ones.
I personally give credit for just students who get the answers right. But I do think that students learn from thinking on their feet so it doesn't bother me to call on students in the class who haven't raised their hands.
I could be wrong, but I guess that I am dubious that this has much to do with price discrimination. It would be interesting to get some numbers on the share of customers in the two types of hotels that use the internet.