"Come the final of any major international competition and you can sure that some broadcaster will make a mind-boggling claim for the number of people who are watching at that very moment." Huw Richards reports

Before you believe them, consider that both ITV and the International Rugby Board will be extremely pleased if the UK audience reaches 15 million.

If only a quarter of the people in the country which presumably has the greatest interest in the match are tuning in, how many do you think there might be in the United States, or India - or for that matter New Zealand?

Those claims arise to a great extent from a misunderstanding of the way figures are calculated. The IRB reckon to have a total audience for the entire tournament - all 48 matches - of around 4 billion, about 20 per cent up on the 2003 figure.

That sounds wildly exaggerated until IRB spokesman Greg Thomas explains :"The way the industry calculates this is to take a snapshot of the number of viewers every 15 minutes. So if somebody watches a programme for an hour, they are counted four times."

Consider that a rugby match lasts at least 80 minutes, that a combination of added time, half-time and pre and post-match analysis can take that up to something like two hours and it is not hard to see how those numbers can mount up pretty rapidly. Just think how many of that 4 billion you have accounted for by yourself while watching this tournament.

The IRB has concluded more than 60 licensing agreements for the competition - the largest of which are, unsurprisingly, in France and England.

Analysts from French media group OMG reckoned the global audience for the opening match, France v Argentina, at just over 20 million. Around two-thirds of these were from France, half of the remainder in the UK.

Next on the list, intriguingly was Russia with 1.744 million. There were 266,000 viewers in Argentina, 333,000 in Ireland, 297,000 in New Zealand, 126,000 in Italy and 99,000 in Australia.

The list is not exhaustive - it excludes for instance Japan and South Africa - but it shows the extent to which audiences are reliant on those two major markets.

Thomas says,"It is the audience numbers for particular matches in the large markets that are of importance to advertisers."

On this basis, both broadcasters and advertisers have reasons to be cheerful.

France's viewership rose steadily for their big games - from 14m for Argentina to 14.5m for Ireland, through to 16.6 million for New Zealand and 18.3 million, the largest ever audience for rugby in France, peaking at just over 20 million in the last few minutes, for the semi-final against England.

Broadcasters TF1 had pulled in 47 million Euros in advertising revenue by the end of the quarter-finals, making their investment of 80 million over two World Cups against production costs of 10 million per tournament look eminently reasonable.

While France's elimination is a blow to them - they'll only be charging 97,000 Euros for a 30-second slot during their final transmission against the 205,000 advertisers would have been shelling out if Ibanez, Chabal and Co had kept Jonny at bay in the last quarter last week - their loss is ITV's gain.

When England played South Africa in the pool stage, ITV's audience was squeezed down - perhaps mercifully in the circumstances - to a little over 5 million by direct competition from Eastenders. There were more people - 7.37 million - watching in France!

British audiences have, though, risen steadily with England's fortunes.

Thomas was particularly delighted with ITV's audience of 11.5 million for the semi-final - meaning that around 30 million people were watching on either side of the Channel - pointing out that this is nearly double the six million who watched the England v Estonia football international on the same day.

Add in the finding by web analysts that there have been more hits for rugby than football over the last couple of weeks and you've evidence that while rugby is still a huge distance from matching the rival code, this World Cup has succeeded in extending the game's audience.