Nokia No Longer a Top 5 Smartphone Vendor - John Paczkowski - Mobile - AllThingsD

Nokia No Longer a Top 5 Smartphone Vendor - John Paczkowski - Mobile - AllThingsD: "Nokia’s transition away from its Symbian operating system to Microsoft’s Windows Phone OS has cost it dearly in the smartphone market."

There's clearly a lesson here, but I'm not sure anyone could articulate it. I owned a Symbian device and the development SDK in 1993.