Here are some reasons why you may have not earned the referral bonus for referring a friend.
1. Your friend registered with your referral code but has not linked a bank account to their Ampli account. In order for you and your friends to earn the referral bonuses your friend will need to link a bank account to their Ampli account.
2. You've already earned the maximum referral bonus possible. You can refer as many friends as you'd like, however you'll only earn a $5 bonus for the first 5 friends that you've successfully referred for a maximum of $25.
3. Your friend did not register with your referral code. If this is the case you will not be eligible to earn the referral bonus.