Users don't like it when you change context, the underlying assumption of the interaction. Usually they can't articulate what's bothering them. In this case, th

Users don't like it when you change context, the underlying assumption of the interaction. Usually they can't articulate what's bothering them. In this case, they are sub-consciously expecting "fair" results, e.g. something consistent with the "Google Bargain" back in the beginning, that Goog would give you great, fair, results, ranked by utility, and add only a few simple, mostly text ads that you are easy to tune out completely if you want to. The Bargain has changed in many significant ways over the years, and things like the Hotels Module certainly subvert the Bargain in a serious way, and I would argue it's unsettling to people (although I don't have hard data on that).