iTunes remains the largest digital music retailer by far in the US, taking a 66.2% share in the third quarter of this year, according to new figures released by NPD Group. That’s up from 63.2% in Q3 2009. NPD claims that Amazon’s share rose from 11% to 13.3% in the same period, meaning that its aggressive discounts and deals are still not taking a big bite out of Apple’s store. The Wall Street Journal reported the news while digging into those discounts, pointing out that Amazon continues to take a financial hit when selling big new albums for $3.99 – such as the recent Kanye West album – since it pays the full wholesale price to labels. If these deals are loss-leaders designed to attract and then retain new customers, the NPD figures indicate they may not be working as well as Amazon had hoped.