All terrestrial broadcasters have experienced double-digit inflation - up to 25 per cent year on year - as ad revenue returns to TV while audiences continue to decline.
September was a particularly bad month for TV advertisers. ITV has been hit since the end of the European Football Championships in July, while five has been blighted all year. September is the first month Channel 4 has been affected.
Young audiences have been particularly badly hit across all channels, and Channel 4 has also suffered from a decline in upmarket viewing.
There was better news for the multichannel players, however, with the Flextech sales house, ids, recording a dramatic increase in viewing.
Chris Williams, the TV director of Starcom Motive, was optimistic that the problem would be a short-term one for the terrestrial channels. "The market is buoyant for revenue but the key programming has yet to kick in," he said.