I share this answer from Adsterra , because with 3k impressions of VAST I have some peanuts
"
We have received a reply from Optimization Department regarding VAST
Please enable vpaid, since most of our advertisers pay for that format specifically.
Our Optimization Department also stated that it would be better to work on the amount of traffic, to have at least 5 000 impressions daily "
wow thats all?!0,10-0,20 $ / Daily
It's because of I asked The Adsterra's Board
It would help if you mention your top GEOs.
However, here's a list of networks with the highest VAST CPMs: TrafficForce, TwinRed, Clickadu, ExoClick.