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.