I'm doing a preliminary study on data from a (niche) social media platform. Studying the correlations between impressions of an object (aka views), interactions (aka likes, comments, ...) and their ratios, it seems that the interacting audience (people who leave a like or a comment) is "capped" after a while. A phenomenon that is best described by this quote from an (old) article about popularity on YouTube:
In a counter-intuitive way, the user response ratio (i.e. number of comments per thousand views) decreases as a function of the number of viewcounts. In other words, as a video is seen by an increasing number of people, it elicits less acute reaction.
I believe that this phenomenon might be more general, but I could not find many references in academic papers or systematic studies of those indices. Several naive questions are quite natural: are there similarities between the ratios in different social media? Are the ratios spurious? ...
Maybe this kind of phenomena is so classic that it is not useful to remark it in research papers, but I would like to find reference on this phenomenon.