You already have that gauge, all you need to do is not upvote links... I think that works pretty good, if you post a bunch of links and they get 0 traction then that's an excellent indicator you're on the wrong path.
The number of 'dead' links and the average points of the 'new' submissions together are a pretty good indicator of what the audience thinks of the current crop of submissions.
The number of 'dead' links and the average points of the 'new' submissions together are a pretty good indicator of what the audience thinks of the current crop of submissions.