The subject says it all.
Something that touches nerves, I would guess.
IT, or it?
There is no answer except “the audience”. Virality is not something that you, the author, put in. It’s something the audience does with your work.
What zarf said, except with twerking.
I believe some topics are more conducive to virality than others.
No, it doesn’t. It doesn’t say why you’re asking, and it doesn’t define what you mean by “a viral topic”. IMHO, that’s important.
Venture capital. (This applies to both IT and “it.”)