Just curious, how do you get your projects viral? I'll be honest to admit, I've worked on side projects before that I've deliberately attempted to manufacture v

Just curious, how do you get your projects viral? I'll be honest to admit, I've worked on side projects before that I've deliberately attempted to manufacture virality (build viral mechanisms off simple games, etc.), but it seems hard. When the simple game with viral hooks is done, I post it up on reddit or HN or PH or whatever, and it never takes off. I know the obvious conclusion is "the game/project sucks", just curious if I'm missing anything else.