American television broadcasters are struggling to persuade advertisers to pay up for commercial slots in the coming autumn season amid confusion over exactly how many viewers actually watch the adverts.
This year's "upfronts" - the glitzy annual event in New York where the main networks showcase their future schedules - was dominated by discussion of how digital video recorders (DVRs) and the internet are undermining the value of prime television ad slots.
But the event was also being used to highlight new ideas that broadcasters are using in order to persuade viewers not to skip during commercial breaks.
Industry watchers predict advertisers will fork out less money during the upfront season again this year, the third year of gentle decline. Last spring, just below $9bn (£4.5bn) was spent securing slots for the autumn television season, with many advertisers deciding to wait until nearer the time.
The balance of power between broadcasters and advertisers has shifted in favour of the latter in recent years, as businesses have found new opportunities to reach their customers on the internet, and as prime time audiences decline.
An estimated 17 per cent of American households now have DVRs that allow viewers to watch shows at a time of their own choosing and easily skip the commercials - and these are more concentrated in the homes of the affluent young so beloved of advertisers.
However, while the upfronts may generate less immediate cash, it is possible the balance of power may shift back to broadcasters later in the year.
On the sidelines of last week's autumn schedule launches, a consensus appeared to be emerging that viewing figures - on which advertising rates are based - should be calculated on the basis of "live-plus-three", that is, to include those who watch back within three days. This effectively splits the difference between the broadcasters, who wanted a "live-plus-seven" standard, and the advertisers, who last year refused to pay for any DVR viewers.
At the same time, there was a warm reception for the line-up of programmes on offer. Bankable favourites such as CSI and American Idol have been recommissioned, Frasier's Kelsey Grammar is making a return to the small screen in a new comedy and the ever-popular Grey's Anatomy is spawning a spin-off show. Meanwhile, many of the new dramas have a lighter, escapist feel to them, reflecting the success this past season of the sci-fi show Heroes.
There is one important element that will decide whether broadcasters or advertisers eventually come out on top.
Most media buyers - who purchase commercial time on behalf of advertisers - are expected to hold fire until next month, when Nielsen, the television ratings agency, unveils a revamp of viewing figures that promises to revolutionise the business of broadcasting. On 31 May, it will start releasing viewing figures for the commercial breaks
With advertisers demanding a much greater degree of information about how many - and who - are likely to be watching their commercials, broadcasters have already started experimenting with ways to keep viewers watching during the breaks. Fox last month interspersed comic vignettes from an animated cab driver called Oleg, while the fifth-placed network, CW, already runs advertiser-sponsored snippets within its lifestyle programming for young adults.
And NBC announced at its upfront that it will experiment with "minisodes" from the comedian Jerry Seinfeld this season. Part entertainment and part commercial, the live-action sketches will air "somewhere, sometimes, somehow" during the television season, Mr Seinfeld said.Reuse content