Limit the viral.
So, users obviously hate viral posts. I get the point that it is helpful for traffic and am not arguing against it entirely. What I suggest is keeping a limit on the amount of viral posts. Currently there's more viral than OC in front - new users will soon start to think that this kind of posts is acceptable. This would be a much smaller issue if, let's say, only every tenth post would be viral. Every fifth? Just keep it lower than it currently is.