Humm, may be John should get a little less excited. Alexa and the WayBack machine was doing that vertical search for a while and for free. I remember also around 2002 they have set a free and public vertical search for a couple of days. They also selling vertical data set on DVD since 2001-2002. And, like Danny says, they are plenty of other free solutions to do that, and thoses seem less complicated to use.
Tags: alexa, wayback machine, vertical,search