Is banhammer the best way to handle link only answers?

Question

I recently answered a question about a very specific piece of code the other day (PHP eval code sandbox break). Since I was on my mobile device I only posted a link rather than try to copy/format a lengthy post using a mediocre interface. When I woke up the next morning I had received the usual link only comment, and my post had been deleted.

I understand why link only answers are seen as bad, I don't understand why instantly deleting the only answer to the question is beneficial. As far as I can tell, a better option would have been to comment and let me update the answer. At least that way the OP could have received an answer, omeone else could have received some karma by editing the answer with link excerpts and $otherthings.

Answer 1

I was the one (or at least one of the people) who flagged that answer as link-only. A moderator saw the flag and must have agreed. My reasoning was, if the link dies, the answer becomes completely useless. Links are supposed to supplement the text in an answer, not replace it. As for allowing you to update the answer, you can. You are able, and encouraged, to edit the answer and undelete it yourself. Unlike questions where a closed question requires a community consensus or moderator action to re-open, a deleted answer can be re-opened by the owner of the answer at will.^* Think of it not as being deleted so much as being sent back to you for improvement before you release it back to the world. Just make sure your edits are substantial enough that it will not be deleted again.

When you look through old posts (both questions and answers) around this site and sites like this, there's a trend of links being vital to understand an answer, yet said links return 404 or don't even point to an extant website anymore. To avoid such a fate, you should at least summarize what is past the link. This can include anything from a quote from the link to an entire paragraph analyzing what is being discussed on the other side of the hypertext. Use your own judgement.

Take an example of an answer which I posted. The question was why a certain decision was made for Ubuntu, and the answer was present on their own website. Instead of linking only to the website, I wrote a quick summary of the reasoning, and then quoted the relevant sections. If the blog post which contained the canonical answer (pardon the pun) was ever to vanish, the answer would still be just as relevant. If I had only mentioned that the reasoning was explained on the blog and then linked to the blog, my answer would have likely been deleted, too.

_{* This is assuming the answer was deleted in the community review queue. You cannot undelete an answer that was deleted directly by a moderator on your own. You can, however, edit it and flag it for undeletion.}

Answer 2

The advantage of a link-based answer is that it is quick and easy to write. This allows the user who asked the question to receive an answer promptly. Hopefully this will encourage them to return to the site next time they have an issue.

The disadvantage of a link based answer, as forest said, is that the link will eventually die. This means the collection of answers which stack exchange depends on to create a knowledge base will also die.

A solution might be to flag the link-based answers and remove them after a short time (week/month). This will give the user who asked the question a quick answer, and give the user who answered time to convert the link information into a better answer.