A few years ago discovered excluding some usernames from a product search can turn reddit results from dozens of hits to none. I noticed those accounts were in all likelihood using keyword notifcations so they could reply to any post mentioning certain model numbers.

In the era of billions of different models of products, there really isn't many people writing about everything. What you get outside of the popular brands and models is nothing at all.

It's more of a red flag than anything if I go looking for reviews and find too much posting about a random product model that isn't a household brand name or obviously popular model. If it's a popular item then I wouldn't have needed to be digging through the internet for reddit comments anyway.