I recently got into a discussion with a relatively new user over link only answers. We were discussing over How to create a button with a CSS-animated background?, and the OP asked

Anyone have any ideas or guides for similar?

The user I was talking to took this as meaning "What concepts are they using." Now, while this isn't a wrong approach to a question like this, the user took it as meaning that he could just give links out, and gave links for an answer.

It has been discussed very intensely at MSO that link only answers are under no circumstances helpful. So naturally, I used my userscript that leaves a comment about link only answers, along with a downvote and a flag. The comment talks about how link only answers aren't ok because of link rot, and it links to Should I flag answers which contain only a link as "not an answer"?. And with that, the user still wasn't convinced that a link only answer was bad.

At our discussion, I told him that it would be good as a comment, because answers need to give useable information. They shouldn't make the OP search an article, and they certainly shouldn't have to search through google, which is what the links were in this instance.

The conversation ended with him saying

You're clearly convinced of your opninion so let's leave it at that, have a nice evening.

So naturally, I feel like I failed.

Now don't worry. This isn't just a rant. I am just giving some background information to my question.

My question is how can I convince a user on why link only answers are bad? This is important, because if I don't succeed, the user will post more link only answers, cluttering up SO even more.

As Seth put it quite nicely

Answers are meant to answer the question, not point to an answer. If all you have is a link you should post a comment