I checked my traffic stats for my link directory and i found out that the traffic exchanges don't really do that much. Most of my traffic comes from the 40+ forums i've joined and have a signature on. Look at my traffic stats for the last 18days for proof of how many people visit my site:
(this link does not link to my website. it is a screenshot of my traffic stats)
It averages out to be 102.78 visitors per day
I am still joining forums as we speak and using my signature to advertise my link directory.
my advice would be to do what i'm doing because it works.