Downloads share of market doubles within six months; Music Week research confirms huge shift in buying patterns for singles.(Digital)

Downloads are fast closing in on CDs as the dominant Top 40 singles format after doubling their share among the top sellers in only six months.

New Music Week research reveals that digital sales are now typically making up around 28% of the Top 40 each week, compared to just 15% when the combined chart launched back in April.

The shift in buying patterns among the very biggest sellers comes as downloads further tighten their grip across the entire singles market. A week ago they made up 63.9% of all singles sales, compared to 47.4% for the first combined chart. But the spread of digital across many thousands of titles--compared to just hundreds for the physical market--has meant the sales are spread more thinly and the CD remains the prevalent format for each week's leading sellers.

However, a comparative analysis of sales patterns between the inaugural combined chart (chart week 15) and the countdown six months later (chart week 42) reveals that within the Top 40 this position is now under threat.

When the combined chart arrived in April, downloads on average made up just 20.7% of each track's total sales within the Top 40, but, by last week, as Domino's Arctic Monkeys debuted at number one, this average had risen to 30.6%. As a consequence, digital's overall share of Top 40 sales rose from 14.6% at the dawn of the combined chart to 28.2% last week.

Given these movements, Virgin Retail's marketing and e-commerce director Steve Kincaid suggests digital could overtake CD as the leading singles chart format within the space of a year. "You can see that trend growing," he says. "It's not just a question of digital sales growing but a question of physical sales dropping. What you're seeing is the digital market has a lot longer lifespan than physical, which tends to be a much faster market."

Napster UK vice president and general manager Leanne Sharman notes that since its service launched in May 2004 the company has witnessed a steady increase in both track purchases and subscriber numbers. "Interestingly, this pattern continued through the subsequent launches of our major competitors in the UK market, which illustrates the size of demand for digital services," she adds.