One of the big things about content going viral is that it has to be about something that people care enough about to read it, or watch it and then share it with their friends.
You can write the best content ever, trick it out with free offers and such, but if its in an area where there are not enough people to achieve critical mass of sharing, its not going viral anyway.
I'm not syying divulge your niche in this thread, just saying that is why in general many viral pieces are mass market, cute, or funny or horrible. And most of them were not made with the intention of going viral, they just did.