From VoIP.ms Wiki
The referral program allows you to receive VoIP.ms credits for every friend you refer. The more referrals you make, the more credits you make. In order to get your credit, your friend has to open an account, deposit funds, make their first phone call and funds will be automatically added to your balance. The referral program can be found in the customer portal under "Finances" and "Referral Program".
0 up to 19 referrals: you get $10 (per referral) and your friend gets $10
20 up to 34 referrals: you get $15 and your friend gets $10
35 up to 49 referrals: you get $20 and your friend gets $10
50 and up: you get $25 and your friend gets $10
By logging directly into the customer portal, you may directly share your unique link, share it on social media or directly invite your friends through e-mail.
You can also closely follow how your unique link is doing.
URL Accessed: Track how many times your unique link has been accessed by your friends.
Signed Up Friends: Track how many friends have signed up using your referral code.
1st Call Friends: Track how many friends have deposited funds and made their first phone call.