Registere Btc Nano official website, and you will have 100 BTN! If you invite friends to register, you will get another 40 BTN, and your friends will get 10 BTN.Invite over 100 people, you can get 1000 BTN, get BTN with your friends together!

Ref - https://www.btcnano.org/index.html?invitedId=732801   
No ref -   https://www.btcnano.org/