For as long as the idea of the 'mobile internet' has been around, we've thought of it as a cut-down subset of the 'real' Internet. I'd suggest it's time to invert that - to think about mobile as the real internet and the desktop as the limited, cut-down version. [...]
Our mental model of how and where you used 'mobile' was that it fitted into specific, occasional places and times where you were walking or waiting or needed a single piece of information and didn't have a PC [...]
Mobile is not a subset of the internet anymore, that you use only if you're waiting for a coffee or don't have a PC in front of you - it's becoming the main way that people use the internet. It's not mobile that's limited to a certain set of locations and use cases - it's the PC. [...]
This is why thinking about 'mobile' as another bullet point next to 'SEO' misses the point: mobile becomes the platform, and it's a much richer and more powerful one. What happens when almost everyone on earth has a pocket supercomputer connected to the internet? It's not a subset of the internet - it IS the internet.