There is something magical about turning complicated battery capacity ratings measured in mAh into number of hours, which is much simpler to understand. Knowing that mobile devices consume varying amounts of power at different rates, this idea would be difficult to implement unless it was marketed for two of the most popular smartphones such as Apple iPhone and Samsung Galaxy. Regardless, the idea of framing a product with time instead of technical language is quite brilliant.
Update: I found a similar concept being used for a flash drive called Gigs 2 Go. Treating storage as a disposable medium instead. Immediate, simple, cheap and small, instead of slow, permanent, expensive and bulky. Certainly an example of how perception towards data storage has changed over the years.