When I write, especially for business, I like to come back a day later and read out loud what I've written and make sure that my sentences are clear. One way I ensure clarity is with a careful use of commas. I believe that it's a courtesy to my reader and avoids misunderstanding in places where the eye might be tempted to combine words or thoughts I didn't intend to combine. Interestingly, not all comma use is governed by rules; some comma placement is a matter of style, preference, and individual judgment.
ON THE OTHER HAND.
Have you noticed the growing tendency to use commas like salt and pepper? The folks at The Onion have! (disclaimer: not everything on this site is G-rated.)
Commas, Turning Up, Everywhere