It's great to see decisions that are made via metrics. I've only got one issue with the post:

"Feature requests have to be normalized by the total number of daily users on the site -> the users who remain silent are not too lazy to ask for something more, they just don't want anything."

I tend to think the users who don't provide feedback are those who are too lazy and/or don't want anything. Either way you can't listen to someone who's "silent".