Apple’s “most advanced” operating system OS X Lion (formally OS X 10.7) hasn’t exactly been their most popular release. According to Apple’s Press page, Lion sales were hot over the first few days, even seeing over one million downloads in the first day. However, since then the latest version of OS X has faced criticism from both users and reviewers alike.

One of the most frequent complaints about Lion is that the user interface behaves too much like iOS, the operating system on iPhones, iPods, and iPads. While iOS has proven successful on Apple’s product mix, this look isn’t a winning formula on computers. Other notable issues include Wi-Fi stability, poor battery life on MacBook Pros, and an inverted “natural scrolling” function. Too read more about Mac OS Lion interface issues, InfoWorld editor, Galen Gruman, has an excellent summary in his article titled, “Lion Letdowns”.

Chitika Insights has been tracking Lion’s market share growth among all earlier versions of Mac OS. We found that a month after Lion’s release it represented nearly 5% of all Mac traffic we see in our servers. Our September installment of this study, authored by Saikrishna Chavali, showed that OS X Lion had risen to over 14% of all Mac impressions. For references sake, Apple’s iOS5 made up over 20% of total iOS traffic within a week of its release.

In our latest report, we saw that Lion had only grown to 16% of Mac OS traffic. Lion is only the third most popular Mac operating system, still well behind Snow Leopard (55%) and Leopard (22%).

Lion’s adoption rate has been less than stellar, to say the least. While we are seeing consistent monthly growth, Lion isn’t taking off the way some had anticipated. From June to September, Lion’s share grew at about 4.05% each month. Since September, Lion’s monthly growth has slowed to a rate of 0.98%.

The once hyped OS X Lion is now in a state of arrested development; they’re growing, but not nearly at the rate newly released operating systems have grown in the past. Historically Mac users are quick to adopt the latest Apple software, as in the case with our iOS5 report, leading us to believe there are some real issues preventing users from making the $29.99 upgrade. However, keep in mind that Lion has only seen two updates since it came out, and it’s likely that they have some solid moves in their pipeline that will get more costumers to upgrade.

We’d like to know what our Apple-using readers think about OS X Lion. Is the criticism unfair, or is Lion really “Apple’s Vista”? Are you satisfied with the upgrade? Have you switched back to or stuck with OS X 10.6 and 10.5? Let us know with your comments!

EDIT: In light of recent contradictions to this study, we’d like to share our methodology to clarify how we got our data.

We pass the user agent to identify the growth distribution of the different operating systems based on the count of impressions coming in through our ad network over the date range in our study. The composition of Chitika’s network covers a fair share of both desktop traffic and mobile traffic, equitable to their respective distributions seen on the web. Just to be certain, we’ve run the numbers again which yielded minor differences (Lion is now 18.8% of total Mac OS traffic, not 16%). Given this, we are confident standing by the assertions made in our prior study.

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