No apologies; joke 'em if they can't take a fuck

Rico says he frequently re-edits the material he posts, even from places like The New York Times or the Wall Street Journal, and he makes no apologies for doing so. (Actually, he's constantly amazed at the poor English they'll publish.)
The most common change is the proper use of the serial comma.
That's when you put a comma between items in a sentence, including the next to last one.
Why?

a) Because it's the right thing to do. (As William Safire says, paraphrasing Lord Admiral Nelson at Trafalgar, English expects all of us to do our duty.)
b) Because it makes things so much clearer.

The classic example, given to Rico many years ago when he worked at Apple (with all due credit to Rani Cochran), was this sentence, a book dedication: "She wished to thank her parents, Ayn Rand and God."
Imagine how differently that would read with a serial comma inserted after Ayn Rand...