the rate of which comments are inflated. Number of total comments divided by number of unique ideas expressed in comments. A higher rate of comment inflation means that there are many comments expressing the same idea(s), while a lower rate of comment inflation means that the idea(s) are expressed in fewer unique comments hence making each comment more unique and valuable.
John: "It's so annoying on facebook when thousands of people comment on a post saying the same thing. It's hard to find interesting comments since they're buried in there somewhere".
Joe: "I know. Many facebook posts have such a high comment inflation rate!"
see also: comment inflate, comment inflator
contributed by: http://flower2fruit.blogspot.ca/2013/11/facebook-created-like-button-for-reason.html