Value of a single customer comment

Hi all - I've been trying to figure out the best way to represent customer comments collected through various VOC touchpoints. Specifically, does anyone have any formulas or best practices on scoping the impact from customer comments. I know I read at one time in the past that a single customer comment, is equilivant to 20 customers...but I don't remember where I saw that or how that was calculated. 
If anyone has any ideas on how to quantify the potential customer impact, from customer comments, I'd appreicate hearing from you. I've tried this in the past and never felt good about the results, and with increased focus on customer feedback right now, I want to make sure what I deliver is not misleading the business.
Cheers,
Allen