What are the arguments for writing efficient programs even though hardware is relatively inexpensive?

How can you know if the person or organization providing the information has the credentials and knowledge to speak on this topic? one clue is the type of web site it is--the domain name ".org" tells you that this site is run by a nonprofit organization.

Aconstruction company is creating a powerpoint presentation describing how they calculate costs during each construction step. they plan to email this presentation to clients. the individual clients will be watching the presentation slide show on their own personal computers. what is the most important formatting step the company should take to make the text readable and pleasing to the eye?

The north and south regions had very diferent economies in the 1800s.