The revelation that Nokia tested out an Android-powered Lumia well before it negotiated the sale of its devices business to Microsoft must have come as a surprise to precisely no one, least of all Microsoft.

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Nokia announced in 2011 that it was dumping Symbian as its primary smartphone OS and moving to Windows Phone. And ever since the standard refrain when discussing Nokia has been 'it should have gone Android' .

It's an understandable position to take — Android is the biggest smartphone OS in town, accounting for well over three-quarters of all smartphones sold , and has been nibbling away at Nokia's declining-but-still-huge non-smartphone business in emerging markets.

The theory goes that as Nokia couldn't beat Android, it should join them. It's an appealing suggestion: the all-conquering Android ecosystem paired with the design might, brand recognition and supply chain relationships of Nokia would seem a great match.

Take Nokia's app problem, for example: opening up the Windows Phone store on a Nokia handset is a dispiriting experience, a ghost town compared to Google's Play. Nokia and Microsoft will tell you the number of apps is not the important thing, it's making sure you have good-quality apps. Alas, it's not succeeded in having either — something which going Android would have fixed up a treat.

Such a move could even have helped Nokia's bottom line: Google gives away Android for free while, even with the $250m per quarter Microsoft gives Nokia to use Windows Phone, Nokia still expects to pay Microsoft licensing fees this year .

Then there's the devices themselves: imagine Nokia's desirable design wrapped lovingly around the Android OS — who wouldn't want that? After all, Nokia managed to shift millions of handsets running Windows Phone, which must be in no large part down to the hardware — imagine what it could have done with a more familiar OS and that self-same engineering .

And instead of focusing its mobile app making efforts on Windows Phone, with its rather limited audience, Nokia could have turned out its apps — maps, imaging and the like — onto the biggest app market in the world .

It's a somewhat simplistic picture, of course: apart from Samsung, pretty much none of the other hanset makers have any real share of Android hardware sales to speak of. Just going Android is not a panacea to a smartphone maker's troubles, particularly now, when Samsung has grown to dominate the market to such an extent .

It's similar picture for the Windows Phone market too — apart from Nokia, no one else is shifting much in the way of Windows Phone devices — but even the Android also-rans like LG, Lenovo or ZTE are still outselling Nokia's Windows Phones by a significant margin.

Maybe in 2011, Nokia should have gone Android. Who knows — it's impossible to predict how the last two and a half years would have played out if it had. But in 2013 it's a different story. For better or worse Nokia, even before Microsoft made its bid, was as wedded to Windows Phone as Microsoft.

Sure, without Nokia, Microsoft would have had to go back to square one with its mobile ambitions, without a significant partner to make devices bearing its OS. But, as the Nokia acquisition, it didn't really want a partner, it wanted a manufacturing arm, so perhaps BlackBerry would have done nicely .

In short, Microsoft had other alternatives. But how likely was it, really, that Nokia would have dumped Windows Phone and gone Android next year? Not at all.

All of Nokia's smartphone app making focus, its developer outreach, its integration work, its partnership efforts were tied to Microsoft. Even its hardware was yolked to Windows Phone — remember, Microsoft dictates what the front of any handset bearing its OS looks like. While getting Android to work on Lumia "was not a Herculean engineering effort" according to the New York Times, which broke the story, unpicking the Nokia-Microsoft partnership would have been. One device running an OS is an easy job; a whole company tooling up to do the same is not.

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You could argue that Nokia could have gone for a dual-OS strategy, as all other Windows Phone manufacturers have, and produced Android handsets alongside Microsoft-powered ones.

Not a bad idea, though the idea of Microsoft supporting and cooperating with Nokia to the same degree once it changed tack seems improbable in the extreme.

Nokia turned the supertanker around once in 2011 when it moved from Symbian to Windows Phone , it's highly improbable shareholders would have stood for a repeat move in 2014. They've experienced one OS regime change as a very bumpy ride, they won't put up with another.

At least in 2011, Symbian sales were sizeable enough to keep Nokia afloat while it ramped up Windows Phone shipments. Trying to use Windows Phone to keep it afloat while it moved to Android would be rather like using a lead weight as a life jacket.

There was a time when Nokia could have gone Android, and maybe even done well from it. That time however is well and truly past — and the curiosity of a Android-powered Lumia that Nokia serves to remind us of that fact.

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