I can tell you that doing signature with just your ref doesn't bring in too many people. I have tried that before and it does work, it does bring a few amount of people, like maybe 1-2 people and that depends on how active you are in bitcointalk as well, you need to constantly write even for that.
Really depends what you say and do, if you started the Hodl thread then you'd likely get a ton of referalls from your signature that way. I tend to see rough viewing figures because I post charts sometimes and it depends on where or when you post, if you are the last post on the page then less people see you perhaps and it can be that simple.