If you do not receive any referral bonus, it is possible that your referrals are not sharing their internet bandwidth with Honeygain.
To check if that is the case, open Dashboard and choose the Transactions history view on the left. You will be able to see all credit transactions that are happening on your account. There you could see how much referral bonus you had gained for the previous day. If you do not see any transactions coming from your referrals, but you do have friends on the Referral list, it means that your friends do not have the Honeygain application installed and open and/or are not sharing their internet bandwidth.