Chartboost giving no revenue?

Zwire

Hi all,

I made some impressions and a few clicks with my game with static interstitials but Im not earning anything.

Does Chartboost only pay per install?

If so, then whats the point of these ads since almost nobody installs anything. The same ads are shown time after time again.

I dont get any money so maybe its better to remove those ads and only have admob since they do pay per impression?