ORIGINAL: Rob/PA Bowyer
The only thing rubs tell you is that a deer was once there. There is no garauntee they will ever be there again. Rub lines are another thing though, they might show you a bucks occassional travel route. Sign posts are rubs that buck return to from time to time but it might be once in a month or weeks at a time.
I like Jeff, don't hunt rubs, rubs are just a good sign that a buck was at least in the area.
I'll agree with Rob's post for the most part. I've too seen some large rubs in the woods that I hunt, but have rarely setup in an area just because of a rub. Like everyone else has said, you never know when a buck might come back to a tree that is rubber, if they ever do.