Should I delete or vote to close?

Question

If a question I have asked turns out to be a dud or a duplicate or for whatever reason should be closed, should I vote to close or just delete it?

In some cases like this question they still do receive quite a bit of attention, so it might be better to leave it up to direct users to a (possible) better solution.

Whereas with some questions that are just terribly formatted, or are poorly researched, or are not suited for this site (theories etc.) What happens then?

Is it better to VtC or just delete it? What happens to closed questions?

Answer 1

Duplicate questions can serve a purpose by providing "signposts" to point future visitors in the right direction. Consider this scenario:

1. Somebody has a question.
2. They use their favorite search engine to find an answer, but get no suitable answers.
3. Having no luck, they ask a new question.
4. It turns out a similar question already exists, but they didn't find it for some reason. (Maybe it was phrased differently? Maybe it used different terminology?) In any case, the wonderful experts here know exactly what the person is talking about, and flag it as duplicate.

Later:

1. Somebody else has the same question.
2. They perform the same search, and find a signpost saying "the answer is right this way".

Hooray! Much faster. In fact, a duplicate question that gets a ton of traffic is a good thing, since it's helping a lot of people find the real answer they need.

TL;DR: No, you don't need to delete duplicate questions. Closing them is usually fine.