At a recent IPA TouchPoints seminar, David McEvoy, marketing director for outdoor contractor JCDecaux, called for greater measurement of all consumption outside the home to respond to the "fundamental structural change" in the media environment.
He pointed out that people are spending 51% more time out of the home than they were 10 years ago, with a further 20% rise predicted by 2012.
McEvoy says: "Time spent out of home is going to be greater by 2012 than time spent in the home awake. The media concept of out-of-home is going to be increasingly important in the next five years."
He has coined the term the "M-generation" - a generation who have grown up with, and only ever known, the mobile phone.
"TouchPoints measures both in and out-of-home, but only measures the latter to a certain degree," McEvoy says. "In the age of mobile phones that carry television and internet, it is increasingly important that there is more depth to the measurements."
McEvoy's point has already been recognised by the industry - measurement bodies like Barb, Rajar and Postar are all working to develop a tool to monitor who is doing what, where and when with their media choices. But while acknowledging the issue, many in the industry believe it is not the most pressing, so will McEvoy's call fall on deaf ears?
To date, no one has met the challenge of measuring out-of-home media consumption - the logistics have proved too complicated.
Jamie Ball, the sales director at Avanti Screenmedia, which sells advertising for the pub screenings of Setanta Sports, fears the lack of an independent body measuring pub television viewing gives some agencies an excuse to ignore the channel in the glut of advertising options.
Ball adds that when in-home viewing figures drop, sporting events screened in pubs could be part of the reason, but there is no way of proving this.
"We know these people are watching it somewhere, they're just not consuming at home and we need to know where they are," he says.
But consultation by television audience measurement body Barb suggests that measuring viewing habits outside the home is low down on the list of priorities.
Bjarne Thelin, Barb chief executive, says he is interested in any technique that could make out-of-home measurement possible, but for now, in-home is top of his list.
Thelin says:"The Barb service will be what its underwriters determine it should be, and what came clearly out of our consultation was that, if we were going to measure out-of-home viewing, it should be something very separate from in-home.
"The industry has given us a priority that in-home needs to be the best it can be first."
So, for now, Avanti Screenmedia and co must rely on their own research. For their peers that sell advertising on the radio, the problem is less relevant.
Rajar, the radio listening measurement body, already measures out-of-home listening extensively, with participants noting what they listen to in the car, office and "elsewhere", while trials on the Arbitron PPM electronic meter are currently taking place in conjunction with Barb, which should be able to distinguish between listening in and out-of-home.
But for Simon Blackburn, head of radio at MPG, out-of-home is still a very small section of the market. "Capital Radio, for example, has 97% of its listeners on traditional analogue radio, so it's that 2 or 3% impact we're missing, and at the moment I'm not that worried about it," he says.
"Right at this moment, there aren't enough people consuming media on their mobiles for us to need to know the figures."
Perhaps then it is too soon to be concerned with the relatively small number of people who choose to tune their mobile phone into their favourite radio station.
No one is denying there is a need to broaden measuring systems at some point, but until the average consumer is catching up with last night's EastEnders on the latest hand-held device, perhaps the already over-stretched monitoring organisations should be left to concentrate on the more immediate, and prevelant, audience behavioural patterns.
- A report released by Continental Research's International Convergence in May suggested just 6% of UK adults will be using mobile TV by 2010
- An inconsistency between content offered by different mobile providers is being blamed in part, with Vodafone streaming live channels on mobile, compared to 3, which only offers short clips
- Statistics from the same company show that, by 2010, 10 million people will listen to MP3 files on their mobile device, while it predicts that by that time 24% of the UK population will access the internet on their mobile
- Radio is slightly further down the track. To date, 47% of mobile phones currently sold by the Carphone Warehouse are radio-enabled and, thanks to the company's partnership in 4Digital Group's multiplex bid, the presence of a radio chip in mobile phones could become standard.