According to Jim Dalrymple at The Loop, Apple's US retail desktop revenue share for October was 47.71 percent, up from last year when its share was 33.44 percent based on figures from market research company NPD.
NPD measures in-store and online sales to compile the numbers, but as Joe Wilcox of Betanews points out, the company did not issue a report with this data.
Observers suggest those impressive figures have been significantly boosted by the launch of a range of new bigger yet leaner iMacs, displayed around Apple Stores and online on Apple's welcome page.
However news of those new models arrived on 20th October, while a high-end iMac, powered by a 2.66GHz Intel Core i5 quad-core processor, wasn't available until November. Strong sales in just over a week of shopping would have been needed to boost Mac desktop sales to record levels.
Stephen Baker, NPD's vice president of industry analysis, issued words of caution when asked by Betanews if Apple could build on or even maintain this percentage share over time. "While those are great numbers, that's probably not sustainable."
"Apple gets a huge bump out of new products that no one else gets. Those [share increases] haven't tended to be sustainable in the long term."
Baker also added that this time last year, post a late-September 2008 stock market crash, customers or potential customers thoughts centred around the recession and not shopping.
"You're comparing the [iMac] launch month this year to the month last year when people stopped going into stores to buy things," Baker said. "To some extent it's a little bit apples and oranges."
NPD also insisted Apple captures more revenue share on much smaller sales due to the cost of buying a new Mac. In October, the Mac desktop ASP was US$1,338, down from $1,390 in April and $1,581 in October 2008, according to NPD. By comparison, Windows desktop PC ASP was $491, or nearly $900 less than the Mac desktop.
Those new iMac models are much improved, offering a new RAM ceiling of 16GB, double the maximum memory of previous models, and can be configured with up to 2TB of storage.
The low-end £949 21.5-inch iMac model, features a 3.06GHz Intel Core 2 Duo processor, 4GB of RAM, a 500GB hard drive, and Nvidia GeForce 9400M video circuitry.
A £1,199 model features the same specs other than a 1TB hard drive and the Radeon HD 4670 video card.
The £1,349 27-inch model features the same specs as the £1,199 model, but with the 27-inch display.
The £1,599 high-end model, brings the iMac product line to new performance heights. It's powered by a 2.66GHz Intel Core i5 quad-core processor and features a Radeon HD 4850 video card.
For power hungry users, a configure-to-order option will swap in the Intel Core i7 chip for the Core i5.
Before the October revamp, the last round of iMacs were released in March of 2009 and featured a 20-inch model powered by a 2.66GHz Core 2 Duo processor, which for many failed to entice.
Apple also introduced a new improved Mac mini in October, which seems unlikely to have significantly helped this latest record percentage share for desktops in the US.