In case that others don't know:
The referral program works on a commission-based system where you (the referrer) gets a 5.00% ETN bonus based on what your referrals mine. This a bonus 5.00% on top of what your referrals are mining – it does not deduct from their mined total.
As an incentive for your referrals to use your code, they will also get a 1.00% bonus based on what they are mining.
So for every 10 ETN mined by one of your referrals, you will get 0.5 ETN and they will get 0.1 ETN as a bonus!
In addition, referrals are for life. So every person you refer becomes a small but steady stream of passive income, provided they keep on mining.