I'm reading the article as validation for viral marketing, as targeted towards the big link-sharing sites. I don't remember the last time a startup hit the fron

I'm reading the article as validation for viral marketing, as targeted towards the big link-sharing sites. I don't remember the last time a startup hit the front page of Reddit. Surely it's happened, but I thought it would happen more than it has, since that site is about sharing links to things on the Web.