"Here is the e-mail that I sent on chips I sold to someone who buys from you"
"Thats why I love this hobby!"

You're contradicting yourself.
1. you are emailing David's customers....that is undermining.
2. you "love the hobby," yet are willing to attack a man who not only loves the hobby, but deals in chips for a living. Don't play with someone's livelihood.
Mixing business and pleasure...apples and oranges....AND you have to make a nasty post. THAT I do not understand. You could just have easily posted your traders and left the (unnecessary and uncalled for) "David dig" out of your post.
I do believe an apology is in order. Do the right thing.
MP