As far as I understand you allow from your website push notifications for other websites(Propellerads Ads). So if you collect a lot of followers they can simply bann you one day and keep earning your money for all subscribed people. Is there a way to secure such a situation code wise? You have absolutely no controll and Propellerads might be trustworthy but money often get's the worse out of good people. I'm not sure about this type of advertising since it's pretty new. The only idea I have is to get a new domain, let people subscribe to it and make kind of a redirect to the custom Propellerads url or implement their code - but am not sure if they will or can agree to such a construct.