I would suggest that you start a paid directory only is you have a budget to promote it For a free one you can get money via adsense, I was making a dollar a day
If what Jack says is true and directories are a saturated sh!thole, what are you the Toilet paper running around behind him wiping his backside.
You can sell special links, sell your own products or services, if you have any other websites. I would also think affiliate links would do good if you have decent traffic.
So why do you come here? Move yourself somewhere else where the we won't bother you. Try some grammar forums. You'll definitely benefit there. Here you are just among us saturated s.....
Be doing what you want to do and if that is to be using adsense then use it. Apart from taking room up on website it cost you nothing but could be earning you something. 1 penny is better than none penny.