Treasurer Tim Cahill, plunging in the polls, has decided to try to stanch the bleeding by making a media buy in the dead of summer. Cahill is using the internet ad he unveiled a couple of weeks back for television, and has also gone on radio. His strategy of conserving his funds for the last couple of months lies in tatters. What will the buy cost, and will it reverse the political fortunes of a candidacy that has hit a major bump in the road?