I've watched this video so many times I'm almost at the point of memorizing it. There's just so much to learn from EffectiveUI as they explain their thought process when developing for multi-screen (or transmedia). For example, EffectiveUI does a fantastic job dissecting user interaction and the context in which they use digital devices.

Things to consider when building a mobile experience:

It's personal
Always on
Permanently carried
Built-in payment system
Creative impulse
Accurate measurement
Social context
Augmented reality

Enabling users to make, manage, and measure great digital experiences.

Other exciting facts

67% don't like sharing their devices. (It's personal to them)
You can access users 24/7
63% of people have admitted to sleeping next to their phone -with it on- fearing that they're going to missing something

Mobile allows you to understand your customers better because the device provides information about their geo-location and overall checking habits.