Sure. What I wanted to say is just, that you can create a measurement for low-quality posts through dividing the number of flags and/or downvotes the post got b

Sure. What I wanted to say is just, that you can create a measurement for low-quality posts through dividing the number of flags and/or downvotes the post got by the average number the other posts had had. Take the inverse of that product and you have a nice factor that approaches 0 for low-quality posts and 1 for high quality posts. I chose a simple example, but of course you could use a more appropriate statistical method, apply a logarithm afterwards or just choose a threshold and reward only posts with 0.9 to 1. Edit: I just realized I made a mistake. Of course, posts do not have downvotes. Flags would still work, but to a lesser extend, I guess. There has to be another method to identify low-quality posts. Maybe some measurement based on the number of comments, their upvotes and so on. That would get really complex, because these metrics again would have to be ungameable.