I think the duplicate threads rule is pretty much useless unless you implement it strictly. I see lot of people make duplicate threads in Sites and Domains sections everyday and sometimes I report these threads but it takes the mods many days and sometimes weeks to take action. Suppose Mr. X makes a thread to sell a domain and it doesn't get sold and then he makes another one next day for the same domain. After that it gets sold and he makes a profit. After two weeks moderators get to know about the duplicate threads violation and give him two infractions. Do you really think the infractions will hurt him? I think not. A person who is making profit wouldn't be bothered with a few infractions and of course the infraction will expire after a few months. Here are a couple of suggestions 1) Whoever wants to sell in Sites and Domains section make it compulsory for them to use the marketplace options and enter the domain name there. Ban those for at least six months who don't follow this rule. 2) Make it impossible to list a domain more than once by the same member using marketplace options. If you can implement the above two suggestions it will be impossible to make duplicate threads then.