You can be funny and miss the main point by being funny.

I have to admit, I’m not a funny guy. I’m trying to be funny sometimes, and I just love my wife for laughing at my jokes (even if I know people will laugh at her for laughing at my jokes :) )

But seriously, I’m totally ok with not being funny as long as I am getting the message across to the other line clear and simple.
You want to know when being funny is NOT a good thing? Read on.
I posted a simple $10 task requirement at oDesk. It’s very simply I asked possible respondents to just tell me if they can do it straight and easy and not go through the long canned messages. Others are good, others totally missed it, but this one’s special. Here’s the dude’s cover letter:
Job Applicants - oDesk.jpg
I was laughing when I read this. Really, he gave me some entertainment. He was trying to be funny and catchy on his communication. And by being funny he totally missed the receiving end of his communication. So, in appreciation of his hard work, I declined his application and wrote him a simple, straight forward reply:
Lesson: make people laugh, that’s cool. But don’t forget that nothing beats a straight forward, honest communication.