A simple MS Word document, or a Powerpoint presentation, has its limits, particularly the unpredictability in how the page will actually display. With a PDF, you are locking down all those variables.

Simplicity, wit, and good typography.

I think that you could design a terrible logo for a good company with great people and they could build it into a great program. Alternatively you could design what seems to be a brilliant logo for people who are not smart or energetic or are incapable of associating with anything positive and it would become a terrible logo.

There was a time when most people had a choice between two kinds of personal communication, handwriting or using a typewriter. Today, people are invited to choose from a list of (surprisingly exotic) typefaces every time they turn on their computer. I think this has made everyone more aware of the idea that picking a typeface is a conscious choice.

For instance, I assume those "carrots" we have on our keyboards were there originally to express "greater than" and "less than." Then they were adopted by coders, and now they show up all the time in the way email addresses are constructed. At least I think that's what happened.

I believe sans serif typefaces - today upheld as models of neutrality and legibility - were called "Grotesques" in the 19th century because people thought they were hideous. But now we're used to them.

It's a cliché, but typefaces are really just ingredients.