A week after its release, Apple's OS X Yosemite powered 13% of all Macs in the U.S. and Canada, about the same uptake pace as seen by its predecessor, Mavericks.
Seven days later, Yosemite's share of all Macs in North America stood at 12.8%, ad network Chitika said today. Chitika frequently mines its logs for evidence of the operating systems or browsers used by the devices that access partners' online advertisements.
In its first week of its availability, Mavericks' uptake was almost the same: 12.4%.
Both Yosemite and Mavericks were grabbed by a larger percentage of Mac owners than 2012's OS X Mountain Lion, which after seven days accounted for only 5.6% of all systems. The difference between Yosemite and Mavericks on one hand, and Mountain Lion on the other, has been credited to the formers' zero-dollar pricing. Mavericks was Apple's first free OS upgrade, and Yosemite followed suit; Mountain Lion cost $19.99.
While it had seemed reasonable that Yosemite would outpace Mavericks in the early going -- the former was available for three months as an everybody-is-eligible public beta and the latter was not, giving Yosemite a head start -- Chitika's data signaled that such expectations have not materialized.
"That advantage [of a public beta] was relatively short lived, with both OS X Yosemite and Mavericks posting remarkably similar adoption rates by the end of their respective first post-launch weeks," said Chitika on its blog Friday.
Other metrics, however, have pointed to a significant adoption of Yosemite during its beta test period. Web analytics provider Net Applications estimated Yosemite's worldwide share of all Macs at 4% for September, nearly 40 times the pre-launch number for Mavericks.
Yosemite adoption will be important to Apple, as the company has added additional iOS-OS X integration features -- notably the set collectively called "Continuity" -- designed to, among other things, tempt current iPhone and iPad owners to purchase a Mac as well.
At the end of September, Net Applications had Mavericks at 63.5%, down slightly from August, signaling that some of the Yosemite public beta users had fled Mavericks for the new operating system.
Yosemite can be downloaded from the Mac App Store, and supports iMacs as old as mid-2007, MacBook Pro notebooks from late 2007 on, and MacBook Air laptops from late 2008 going forward.