Apple sold 2.2 million Macs in the U.S. in 2013's final quarter, a 29% increase over the year before. Or it sold just 1.6 million, representing a 6% decline.
In a repeat of past discrepancies between market research leaders IDC and Gartner, the two firms on Thursday released very different estimates of Apple's performance in the U.S. for the fourth quarter, making it hard to know which, if either, to believe.
Gartner forecast U.S. Mac sales at 2.2 million for the quarter, an increase of 28.5% over the disastrous fourth quarter of 2012, when Apple inexplicably announced new iMac desktop computers but had virtually none to sell. Apple later blamed the quarter's dismal Mac sales -- down 22% from 2011 -- on the iMac fiasco.
CEO Tim Cook regretted the decision to unveil the new iMacs. "I would have announced the iMac after the turn of the year, because we felt our customers had to wait too long for that specific product," Cook said during an April 2013 earnings call.
But rival IDC pegged fourth-quarter 2013 U.S. Mac sales at just 1.6 million, down nearly 6% from the weak fourth quarter of 2012. That pushed Apple down a spot to No. 4 on the list of the biggest U.S. computer sellers, and let Lenovo squeak into No. 3 for the first time.
Which is right?
Rajani Singh, an analyst with IDC, defended her Mac numbers and argued that when the two firms have come up with wildly different estimates, IDC's ended up closer to the actual mark than Gartner's.
"Gartner overestimated Apple's number last quarter," Singh said in a Thursday interview. "I'm not worried; I think our estimates are closer to reality."
In fact, the two viewed the third quarter dramatically different, too. Then, Gartner projected U.S. Mac sales at almost 2.2 million, down 2.3% from the year before; IDC's estimate was a more conservative 1.9 million, or off 11.2% from the same period in 2012.
Apple does not publish Mac sales figures by region, but only a global total, making it tough to call a winner. But Apple's worldwide Mac sales for the third quarter were down 7.1%.
Singh said IDC's Mac shipment projection was in part based on what she saw as a lack of significant change to the Mac line during the quarter. "Apple didn't come up with any special [Mac] products, or any creative products," she said.
In late October, Apple refreshed the MacBook Pro notebook line by incorporating Intel's latest Core processor, code-named "Haswell," to sync the higher-priced laptops with the MacBook Air, which received the power-sipping chips in the summer. While Apple lowered prices of the MacBook Pro by $200, it did not change the exterior design or follow Windows OEMs (original equipment manufacturers) into touch-enabled notebooks.
A month before, Apple had tweaked its iMacs by turning to Haswell quad-core processors.
The only really new design -- the radically-changed Mac Pro that went from a bland tower to a sleek 10-in. cylinder -- was launched very late in the fourth quarter, and sales were constrained by supply shortages.
IDC and Gartner also had different visions of the U.S. personal computer industry as a whole. IDC appraised shipments at 17.1 million, a small 1.6% decline compared to 2012, while Gartner said shipments reached 15.8 million, representing a substantial 7.5% contraction. The large gap between the two researchers was most evident in the "Other" category, where Gartner placed just 3.2 million machines compared to IDC's 4.5 million.
Apple will reveal fourth-quarter Mac sales at an earnings call scheduled to start at 5 p.m. ET on Jan. 27.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed. His email address is firstname.lastname@example.org.
Read more about macintosh in Computerworld's Macintosh Topic Center.