In sum and substance, for every 4 hours of paid massage you refer to me, you receive an hour free. If you refer to me any combination of number of people and time (meaning if someone buys 1/2 hour or 1 hour, others may buy 1 ½ hours, etc.) totaling 4 hours of massage, you receive an hour free.
Every time it totals 4 hours, you receive one hour free. I will notify you that I have heard from your referral and then again when that time accrues.
Exception being: if any person you referred to me has referred sufficient people that they receive an hour free, that free hour does not count to your advantage. However, if that person refers sufficient people that they get 4 free hours from their own referrals, you will then receive an hour free.