Great post! I'd also suggest when a competitor's salesperson is engaging in negative selling against your company or your product that you try one of the following....

"I know you are, but what am I"

"I'm rubber, you're glue, whatever you say bounced off of me and sticks to you."

Your prospect, who has their ears plugged and is saying "la la la la, I can't hear you" in response to all crazy sales claims they are hearing, is sure to be impressed.