"The 14 million - 15 million unit range is based on various assumptions and is an extrapolation of one month of data, so we believe investors should supplement this data point with other information," analyst Gene Munster told clients Thursday.
He said it's also very important to note that the October data does not include any impact of Apple's new iPod shuffle, which did not begin shipping until the 3rd of November.
Munster, whose current model calls for the Cupertino, Calif.-based iPod maker to sell 14.7 million iPods in the December quarter, believes the first month of iPod NPD data implies the company is likely to beat his estimates.
"It is likely that the impact of the iPod shuffle, which shipped on November 3, will have a material impact on the November and December NPD data and our current expectations for the quarter could prove to be low," he said.
Indeed, speculation amongst industry watchers has been that the new iPod shuffle could emerge as the dark horse of Apple's digital music player line, due to its surprisingly low price point of $79 and compelling form factor.
While Apple has not provided any real-world feedback on sales of the petite player thus far, its vice president of worldwide marketing, Phil Schiller, said in interview last week that consumer response "has been tremendous."
"The early response and reviews have been phenomenal," he added.