Back then I worked in mobile games industry, and our games had one good feature: players could watch video ads for getting inner currency (like diamonds). I suppose it's good for both, players which didn't want to pay got diamonds, and the company had a revenue (even though that was just 20-30% of all revenue).
Now I'm working on web service and I want to add this feature. If free users want to remove watermark, they would watch video ads. I was quite sure there are some ads networks providing this feature, but I couldn't find any.
Who knows, is this feature possible in web application?
For this moment I found Adsterra, which seems to be what I've been looking for.
(If someone will face the same problem as myself).
I will write here about my progress with video ads.
Hey, I'm curious if you managed to use Adsterra for your case? I'm currently looking for the exact same thing. Also created an account with Adsterra, but do not see video ads in the dashboard. Which kind of banner did you use?