As a writer I have started a few trends, nothing viral, but trends non-the-less. Other writers, the real writers, have a network of support and have started trends on Twitter, like the #Iamwriting hashtag. It gets writers talking and others curious, and usually makes the top Twitter trends weekly.
As a promoter, I have done such things as lumping articles into categories, existing or new to get them onto other pages. If repeated enough, (and with 200 writers, I can repeat a lot) it will become an entity all its own. Never be to conservative with your hashtags, but make sure they make sense. For example, I was promoting an article where a guy drove 300 miles with his dead girlfriend and his wheel chair bound mother and I used the hashtag #HeinousCrime. It did not go viral, but it is my firm belief that the article got more hits because of the hashtag. It promoted curiosity and people want to know what prompted that particular tag.
I think on this topic, I will end with the thought that I am going to start a “Self Promotion Saturday!” Why not? Even if I am the only one using the #SelfPromotionSaturday, it will be a fun experiement!