Android has officially hit the big time now that sales of its devices exceeded the Apple iPhone over the past quarter.

The definitive Android smartphone guide

Android's rise is fairly remarkable for an operating system that only just launched in the fall of 2007. The open-source operating system's success is even more impressive when you consider that when it debuted it was already facing a crowded field of OS heavyweights such as the iPhone, BlackBerry, Windows Mobile and Symbian.

Briefly, a look at the numbers: Over the span of a mere quarter last year, Android saw its share of the U.S. smartphone market more than double, as the platform was used on more than 7% of all U.S. smartphones at the end of 2009. The most recent research released by the NPD Group showed that Android-based phones in the first quarter of 2010 accounted for 28% of all smartphone shipments, trailing only Research in Motion's BlackBerry operating system, which accounted for 36% of all smartphone shipments in the quarter. And finally, Android-based phones are now available on all four major U.S. wireless carriers, with the million-selling Motorola Droid so far serving as the platform's flagship device.

So how did this all come together so quickly? Looking back over the past three years, it seems that Google had a very simple but effective plan to push its way into a crowded market. Using a combination of free software, design simplicity and brand clout, Google has succeeded in making an operating system that, in just a couple of years, has grown to rival the most popular mobile platforms in the business. Let's take a look at each element piece by piece:

* First, make it free. One of the most enticing aspects of Android from both a software developer and a device manufacturer perspective is that it's completely free to use, as Google charges no licensing fees for anyone who wants to base their device or application on Android. This is a distinctly different path than the ones taken by Apple and Research in Motion, which both only allow use of their operating systems on their own devices, and by Microsoft, which only allows devices to use Windows Mobile through a licensing agreement.

* Second, keep it simple. When Google went about attracting application developers to its new platform, it made a big deal about the Android software development kit's ease of use. And since Android is Linux platform that uses Java as its programming language, most software developers on the market haven't had much difficulty in writing programs for the operating system.

Google has also gone out of its way to make posting a new application on the Android Market a snap, as the company does not screen any applications sent to the store and will only remove applications if it has received legitimate customer complaints about them.

"We created an account, uploaded our apps and then hit submit," said Ilya Eliashevsky, the product manager for app developer DataViz's Android product line, last year. "Then the app just started showing up on devices and we saw sales immediately starting to roll in."

* Finally, be Google. There have been ambitious platform developers in the past who have tried to mainstream open source in the mobile OS market, but none of them so far have had the market clout of Google. Google's brand recognition not only helps it attract media attention to its initiatives but also helps it more quickly develop relationships with device manufacturers, carriers and app developers. In other words, while you obviously need to develop a strong mobile platform that device manufacturers, software developers and consumers want to use, it doesn't hurt to be the world's No.1 search engine either.

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This story, "How Android Phones Became a Hit" was originally published by Network World .