What about COURTESY?
No thread crapping. If the subject matter of a deal does not interest you, do not post negative comments about it, or about other members, in the thread.
When are negative comments allowed?
* If you know a "deal" is a scam.
* If the post contains improper links, such as click-through referrals, etc. If you know a better link for the same deal, post it in the thread.
* If there is any other reason to warn others about an offer or link. For example, many sites offering free magazine subscriptions have been known to continue billing credit cards long after the subscription was cancelled. Also, if you know a vendor has a bad reseller rating, you are doing your fellow members a favor by warning them.