Advertise your site every where you surf. Some will sign up and never do anything. Don't give up.
Once you do get referrals don't stop doing your own. Remember yes you can earn from your referrals if they work but your referrer needs you to work for him or her to earn . Do your checklist daily. Before you know it you will make enough to pay for your upgrade.
Do not pay referrals to sign up it is not allowed. You and your referral will get kicked out.
Have fun and enjoy.