When someone sees a duplicate, some people vote to close, some authors delete it, some don't, some post a link to a duplicate in a comment, it's all very messy for something that is bound to continually happen.

There should be e.g. a **This-is-a-Duplicate button**, you click it and fill in the url to the duplicate question. That way you get little "**bundles**" of questions which are asking pretty much the same thing, and since some questions are not truly 100% duplicates but just **near-duplicates**, this keeps them together for people who are interested in the general topic. 

A question with duplicates which have a list of them right after the question.