Mobile isn't just about the device. Don't just look at the mobile channel as a series of devices. It's true that your content needs to be optimized and look great across different brands of tablets and smartphones. But mobile is also about the context and behaviors of your customers while they're on those devices.
What are they doing on that smartphone? Are they accessing content relaxing at home, or glancing quickly during their commute? Your content strategy needs to represent a deeper understanding of your users' mobile context and what that means for both your content and experience creation.
For example, I recently bought a new home theater system. As I was setting it up in the living room, I realized that I lacked a particular part to enable the wireless rear speakers. I needed to figure out how to buy that part while I was next to my speaker system so I could examine their part numbers and other information printed on the speakers. I pulled out my iPhone and began searching the web. Plenty of suppliers had the part available, but I made my purchase based on what I needed at that moment: Assurance that it was the right part, trustworthiness of the supplier and a reasonable price. I purchased from the supplier that was able to convey each of those things in the easiest, most efficient manner on my smartphone.