No offense buddy but this is the worst idea that you could ever think off. I had to sell three article directories after they grew to reasonable size in the last year due to the AMR spam involved. And I can say for sure that you hardly get any clicks on ads as those are AMR spam where nobody needs to even login. Even if somebody logs in they quickly post and leave and nobody clicks. Google hates the content to be honest and I have had more than 50K indexed pages without any clicks. And if there is click once in a while it gets paid the lowest in adsense even for the best niches. Just to give an idea. I used to manually moderate for a few days and then I was receiving hundreds of submissions every day and it is IMPOSSIBLE to manually moderate unless you are free for the whole day. And why would you anyways moderate if you don't make any money. Add to that, article directories are banged on by thousands of AMR users every day and they also screw up the server. Been done, done that and left that. Even the people whom I sold off all the directories later sold it off in a few months due to the same problems. LOL. Even the highest possible VPSes on HostGator were not working for them and they were running in massive losses.

My advice would be to remain away from article directories unless you want to screw yourself up for the sake of other AMR users who would definitely spam it to death.