Infolinks is the best choice for you, if you have +1000 uv per day.i own an article directory website.
I am getting 100 pageviews a day without touching all organic mostly given that i only installed analytics on wp posts not on all pages
please refer me some ad networks which pays decent cpm and pays with paypal.
thnks
Yes it is true.Very difficult to monetize 100 unique visitors per day