They are paying because they want to spread awareness of this amazing project of ETN, They have a great dev team and everyone is doing their job perfectly. Keep mining ETN guys, it will give you good results at the end of this year 
Oh, now i see. They were just paying you because you ran their simulator but in reality it doesn't really give you any ETN because they provide the ETN for you. They were just more likely a campaign but on mobile phone while using their mining simulator. So, what if they stop doing that like giving you ETN and they have decided to stopped giving you ETN in the future because they got what they want. I don't know if it is worth it to do that, but it's just like you are watching an ads for every game to get the money.