Sitescout would be a good place to start. However since most of the impressions are from RTB it will be hard to verify which ads are being shown...
You could look into PopAds, PopMyAds, wwwPromoter
Main ones in the adult space are Exoclick, TrafficJunky, AdXpansion, JuicyAds
There's quite a few mobile ad networks that specialize in app installs like Applovin, RevMob, Chartboost, Airpush etc. You might want to check...
Go2Mobi, Avazu, Glispa, Exoclick, Ybrant Digital, Adorika, Iconpeak
there's really a thousand sources out there that I don't have enough time to list. We have all of them (filterable by geo/audience/pricing model)...
US has quite a few. Here's a few sources for Indonesia:
Go2Mobi, Vserv mobi, Affle, Tapgage, Adatha, Adways Interactive, Ad2campaign, Adflex,...
Aditor, 980 Media, All-Star Media Group, BannerSpace, Adsforgambling, Tapdice
Exoclick, JuicyAds, AdXpansion, Reporo, Adultising, Green Point Ads
Theres ogmobi and go2mobi - different companies (incent, and regular respectively)
too bad precise interest targeting doesn't exist anymore on FB, otherwise you could get super granular with pages people have liked
Leadbolt, Go2Mobi, Pocket Media, Propeller Ads
We actually have the original source of this list, and you can search by country/channel/audience/pricing model
Exoclick, AdXpansion, JuicyAds, Reporo, Websponsors, eHealthcare Solutions
Expatica Ad Network Expatads, Exchange Exchange, ExpatFinder, Angloinfo
what type of audience?
SEMRush, Keyword Spy
Zergnet, RevContent, Taboola, Outbrain
$2CPM for Tier 3 countries sounds pretty aggressive. we have a list and you can filter by regions at thalamus co/display/ad-network
Separate names with a comma.