Best ad network for interstitial/popups for mega traffic site ( 250k visits / day ) ?

Advert test
Hey there!

I own a website that is for sharing stuff socially and I get 250,000 visits a day and about 600,000 pageviews.

Most of the is from international, with about 33% from indonesia. However, I do get alot of traffic from USA also ( 350k visits/month )

I am looking for a interstitial ad, or a popup ad that will accept international traffic. I already use banner ads and they work fine, but I want to also do interstitial ad/popup ad. I get about 50 cents CPM from banners.

Can anyone suggest a ad network that might work for me? Thanks!