Where to sell ad space

Hi,

we are monetizing our web using Google AdSense and it works quite well now. However, we have implemented some extra ads space that can not be used with GA. Unfortunately, it can not be used with BSA either because we need the target page to open in a new window and this I was not able to find this option in their code. This limitation can not be removed because the ad pops up when something important is in progress for the user and if they go away, the whole point of using our web would be mitigated.

Therefore I can see the best option either to
1) find an affiliate product for which we can install a code ourselves and which would sell

2) or, to sell the ad space directly.

The problem with 1) is that we do not have enough experiences to find a good affiliate partner - almost every attempt through networks like CJ.com or alike ended in zero sales.

So, I would like to go with 2) - the direct sale. I am thus looking for makret where you can say "hey I've got this amount of targeted traffic for this topic and the ad there is doing that much of CTR, I am looking for someone who will pay at least X per month for that with a contract at least Y months long".

Could you please recommend any such markets that you have good experience with? I have only experience with local markets, but this project is global, so my experiences are useless here.

Thanks a lot!