Small part of a program : d and c versions performances diff.

[Larry via Digitalmars-d-learn]

@Chris :
Actually yes. If we consider the device to run 20h a day, by 
shaving a few microseconds there and there on billions of 
operations a day over a whole machine park, you can enable 
yourself to shut down some of them for maintenance more easily, 
or pause some of them letting their battery lasting a bit longer 
and economies have proven to be in the order of thousands $$ 
thanks to a redefined coding strategy.

Not even mentionning hardware usage which is related to heat and 
savings you can pretend to have over a long run.

By changing some hardware a few monthes after their theorical 
obsolescence, you can save a bit further.

And the accountant is very happy because he can optimize the 
finance further (staggered repayment)

It enabled us to hire more engineers/hardware.

Of course, the saving is not only on this loop but on the whole 
chain. And it definitely adds up $$$.

And there are a lot more things involved that benefit it (latency 
and so on).

Yep. :)