When Admob rewarded video ads are paid? By watching the video or only when you click on the app at the end of the video?

These are my numbers

Impressions 234
Fillrate 90,70%
Impressions 84
Clicks 0
CTR 0,00%
Gained 0,00*

In another placement I just have a small cents by a click. Is this normal?

What alternatives can I use using AdMob mediation?