Horace Dediu on the M7 coprocessor in the iPhone 5s:

When the A series chips were created Apple leveraged the in-house design and cost reduction to make a wide range of products with more than 700 million examples built. Designing a chip needs a broad application domain.

Perhaps this is why Apple chose to describe the iPhone 5s as “forward-thinking”. The M7 and the Touch ID are like research projects whose actual value will be realized at some future time, in probably different contexts.

M is for Mystery