I've been retagging questions on the assumption that:
- It makes it easier to find duplicate questions.
- It makes it easier to find solutions to the problem I currently have, both through the search functionality and in the related questions functionality.
but I'm interested to know whether there's good evidence that retagging improves findability. Apart from increased views because of the edit bump, when a bunch of questions have been retagged, does traffic increase, for example in terms of:
- User-supplied links to the retagged question from another question.
- Questions being closed as duplicates of that question.
- Views of that question.
- Answers to that question.