There's a theory or study that shows evidence that users are more prone to provide reviews if the review is bad than if the review is good. Kind of a "revenge" review.
However, can't find it on Google (nor here) and I need it for an article I'm writing. Maybe because I'm using the wrong search terms or because I don't remember the name of this study.
Anyways, any help really appreciated
Note: It's not Praise-to-Criticism Ratio although it might be related