Sorry I wasn't actually clear - my fill rate from my ad server is 100%.
I'm partnered with Blinkx Media (http://www.blinkxmedia.com/) and now that I'm serving ads in friendly iframes my fill rate of paying ads has dropped to 20% and Blinkx Media are passing the ad requests over to my in-house passback ads - I hope that makes sense.
According to this blog post from monitize more - they've experienced a similar problem as well (http://www.monetizemore.com/blog/are-the-new-dfp-ad-tags-gpts-decreasing-your-ad-revenue/).
For some reason, even though the iframes are on the same domain as my website (i.e. firendly iframes) they are still affecting real time bidding ad revenue. Maybe advertising are not getting the info they need or something - I'm not sure.
It's really hard to balance performance with ad revenue.
I realise this is a tricky issue, but I'm really not sure how to proceed - its amazing to have a community like this to turn to.
I've just got off the phone with my ad network and they have confirmed that their adserver AdConductor can not handle asynchronous tags so the issue was on their end.
Revive Adserver v3.2.0 (a beta was released recently) has a new feature: asynchronous javascript tags. See also:
http://www.revive-adserver.com/blog/beta-version-of-revive-adserver-v3-2-0-released/
Do note, though, that expanding ads will never be possible, in case of iframes (even friendly iframes).
BravoEchoN got a reaction from andrewatfornax in Asynchronous Js Tags Reducing Revenue