Download sales look set to play a vital role in who will scoop the coveted Christmas number one in the UK charts.
Nizlopi are currently at number one with JCB
The race for number one and demand for digital music players will push sales to an all-time high, the British Phonographic Industry (BPI) predicted.
The top chart slot could be decided by downloaders for the first time, the Financial Times said.
Weekly digital sales now regularly top 650,000, but may reach the one million mark for the first time, says the BPI.
The trade association said download sales had already topped 23 million this year, a 400% increase on last year.
Downloads now account for about 70% of weekly singles sales, compared to just 25% this time last year.
Downloads made up 24% of sales of Nizlopi's single JCB the week before it reached its current number one position, a spokeswoman for the band said.
The BPI also anticipates an expected boom in CD sales and says the week leading up to Christmas or the following week could see the biggest week for the British single for years.
As Christmas singles were "perfect stocking fillers", the final week of the year always saw a "massive boom in sales", said BPI spokesman Matt Philips.
"Although you can't put a download under the tree, seven out of 10 singles are sold as downloads and they are going to play a significant part in deciding this year's Christmas number one," he added.
Downloads are also expected to be boosted by online sales of X Factor winner Shayne Ward's single, available as a download before it is in the shops.
X Factor winner Shayne Ward is among artists hoping for No 1
Bookmaker William Hill are calling his single That's My Goal a certainty to reach number one for Christmas.
It has slashed his odds of topping the charts from 1/7 to 1/9.
Spokesman Rupert Adams said: "Even at these odds we are still taking weighty bets on Shayne and it now looks like a certainty that he will have the Christmas number one.
"If it carries on like this we might even close the betting."
The BPI has forecast that 2006 will be an even bigger year for digital music. MP3 players were a popular gift last Christmas, and prompted a 30% increase in download sales in the last weeks of 2004.
Last week a study from Motorola suggested British consumers were the biggest legal downloaders in Europe, spending 75p a month - three times more than in Germany, Italy or France.
However, a survey for AOL found that only 40% of UK consumers said they understood the law in respect of music downloads.
The survey by IpsosMORI found 77% of people who download music had used an illegal website at least once. And 51% said they used only illegal download services.
It also revealed that illegal file-sharing networks such as Limewire and Kazaa were still more popular than legal download sites.
AOL launched its Play Legal campaign on Monday to help people understand how to enjoy online music legally.