Microsoft, Google and cloud tech news: Do Android and Windows really have 35% of the tablet market?

A new report out today seems to show Android and Windows making headway in the battle to topple Apple's iPad at the top of the tablet market.With the iPad accounting for 61.3% of shipments in Q2 2011, Google's Android takes 30.1% and Microsoft's Windows takes 4.6%, reports Strategy Analytics.However, the numbers are based on "sell-in," meaning the amount shipped to retailers, whether those be physical stores or online retailers like Amazon.com.

Tablets that sit on shelves and never get bought by consumers are counted toward the total.In pictures: The 11 hottest Windows and Android tablets unveiled at CESWhile Apple sells nearly every iPad it is capable of producing, results from other surveys suggest that demand for non-Apple tablets falls short of supply.A good measure of everyday tablet usage is one that looks at how many people connect to the Internet, since nearly every tablet owner uses the device to surf the Web.By that measure, the Web usage tracker Net Applications recently found that the iPad accounts for 53 times more use than the most popular Android tablet.The Strategy Analytics numbers give the iPad 9.3 million Q2 shipments, Android 4.6 million, 700,000 for Windows and 500,000 for BlackBerry's QNX.I spoke with Strategy Analytics researcher Neil Mawston today, and he explained that the firm tracks shipments to stores, but not sales to consumers.

In the case of Apple, factory shipments to Best Buy and even Apple's own retail stores count, although tablets purchased by consumers on Apple.com and delivered to their homes do not.

Apple recently reported sales of 9.25 million iPads in the second quarter,so Strategy Analtyics' numbers for Apple seem to be spot on.Strategy Analytics is tracking e-book readers separately from tablets, and hasn't reported those numbers yet.

That excludes devices like the Android-based Nook Color from today's figures.Sell-in is a standard metric to determine popularity, since stores usually don't order devices they don't expect to sell. But if there is a large gap between shipments to stores and sales to consumers for certain types of devices - specifically, Android and Windows tablets - then Strategy Analytics would be underestimating Appe's dominance of the tablet market. Certainly, the lines at Apple stores and weeks-long wait times for the iPad suggest Apple is just barely keeping supply ahead of demand.A new report by Good Technology found that more than 95% of tablet activations among enterprise customers were iPads. The survey was based on "thousands of customers across every major industry, including 49 of the Fortune 100," and also looks at the second quarter of 2011.In May, Fortune ran a chart based on a Nielsen survey showing that the iPad captured 82% of the U.S. tablet market.Some of the surveys showing higher iPad share are based on total usage, rather than recent shipments.

Therefore, the Strategy Analytics numbers showing Q2 shipments to retailers show good progress for Android, and perhaps are indicative of future sales, even if consumers aren't buying up every single Android tablet on the market today. A year ago, only 2.9% of tablet shipments to stores were Android devices.Last year's low numbers were reflective of the fact that the iPad had just arrived and the only Android tablets were based on the phone version of the Android operating system. At the very least, the last year has seen Google optimize Android for larger screens and numerous device manufacturers place big bets on Android, hoping that the tablet market will come to be dominated by Android just as the mobile phone market has been.But huge device production is just the first step.

To make Android tablets a success, people have to actually buy them.Follow Jon Brodkin on Twitter.