There are several examples of link only answers which are as we know deprecated and not very useful for this site. Usually someone comments on the answer requesting a summary of the link, or similar request, but many times this request is not fulfilled by the OP (for whatever reason) and months or years later it remains a mere link.
My question is what someone else, who thinks that the content of the link provides a useful answer, should do? Should they:
1) Expand the answer - the downside to this approach is they will not gain any rep. for their work, and may be disinclined therefore to bother themselves. Even someone who does not care about rep. points may feel reluctant to have their hard work put in someone else's name.
2) Post a new answer and flag the old post for deletion or demotion to a comment on the question. The old post deserves to at least be demoted to a comment, and this would solve the problems of the first approach, but is this the best way of correcting the matter?
What are your thoughts on the matter?