Is my answer a comment or an answer?

Question

I wrote an answer (screenshot for the sub-10kers) to a question that, IMO, is off-topic, but given that I'm a newbie here, I honestly don't know. I assumed that since it was upvoted, already had two great answers, and wasn't closed, it was probably fine, if a bit off.

Within ten minutes (I don't remember how long, and it just says "four hours ago" for each) the answer was deleted, and under it was a comment by a mod:

This is a great comment, but not an answer to the question.

I disagree with the second half of that. I think it's a valid answer because it's one explanation for why the original asker suddenly saw an uptick in ads based on a certain thing, soon after talking with an expert about that thing. While it's certainly not an informational security answer, it is an answer to the "or was the targeted ad pure chance" part of the question -- namely, "no, but it also has little/nothing to do with your call".

Because of this, and on the recommendation of a few members of chat, I'm taking it to meta. Is my answer valid? If not, please explain why not, because I really don't get it.

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It was originally converted to a comment, but because it was cut off -- and, to be honest, I was a bit miffed -- I deleted it. After some thought, I decided it was worth noting, so I copy/pasted the first paragraph into a comment on the question.

^{For the purposes of this meta question, please ignore whether or not the answer is actually correct. I'm fairly certain that it's at least a possibility, but that isn't what's under discussion.}

Answer 1

I am happy to explain my reasoning for the move.

Although your suggestion is a perfectly valid, possible cause for the effect that prompted the question, it is not an answer to the question asked.

I truly believe that the asker would benefit from your suggestion, so I converted to a comment.

Answer 2

The reason for it to get converted to a comment(IMHO) is the same as it was made a comment:
It really only applies to that use case/cause, but ignores the actual underlying question:

How come I receive online ads for a product related to a phone call I made?

This was the real question asked, albeit in a round about manner. Your answer in the screenshot really only puts it into the pin hole of this specific use case. In fact I'd argue that the question needs an edit to reflect the true nature of it.