As revealed by ±±¾©Èü³µpk10 (18 February), the outdoor industry's efforts to measure trackside sites and Tube panels had been derailed by concerns about accuracy. The sites were originally due to be included on Postar at the end of 2004.
However, Maiden has started publishing its audience data ahead of its verification by the IPA and is attempting to get the specialists to use the figures as a trading currency.
David Pugh, the managing director of Maiden Outdoor, said the company was working towards Postar-approved rail research.
"We will be available on Postar later this year - there are aspects of the research that we are refining to get Postar accreditation. In the meantime, these are our numbers and we are perfectly entitled to use them," he said.
Lynne Robinson, the IPA's director of research and a member of the Postar board, added: "We are looking forward to Maiden being part of and complying with Postar."