Although Apple has not yet officially announced its sales numbers, Chikita Web traffic reports show that as much as 3.2 percent of Web traffic from Mac users is coming from those running Mountain Lion. CNET said these figures translate to more than 2 million copies of OS X 10.8 Mountain Lion being sold in only 48 hours.
According to Chitika, "With 3.2 [percent] of all Mac users upgrading to OS X Mountain Lion in the first 48 hours, Apple's latest operating system stands to do much better than its predecessor OS X Lion, which experienced only a 14 [percent] market share after [three] months on the market."
Currently, the most popular of Apple's operating systems is 10.6 Snow Leopard, with a Mac market share of 45.51 percent. After that come last year's upgrade, 10.7 Lion. Many users chose not to upgrade to Lion due to poor reviews. Word of mouth in the case of Mountain Lion has been stronger, however, meaning it is more likely that Snow Leopard users will upgrade straight to Mountain Lion.
Mountain Lion has several advantages over its predecessor, especially its price. The new OS is priced at $19.99, the cheapest operating system upgrade offered by Apple in decades. Traditionally, Apple had charged $129 for an update every two years, although prices have been significantly lowered since Snow Leopard.
Apple announced in July that anyone who bought a Mac between mid-June and Mountain Lion's release Wednesday would receive a free copy of the new OS. This promotion likely had something to do with the dramatic rise in its market share, as well.