I have a few questions about the referral system.

Q1) At what point do I 'level up' my referral system?

Q2) How many referrals do I need to unlock the referral rewards?

Q3) How do I earn 'referral points' to spend on the said referral rewards?

Q4) At what point do I earn Diamonds for referrals?

My account summary said I referred three people, yet nothing seems to have changed on the referral page. I was curious and I couldn't find anything about the referral system on the forums.

Q1-3. Your referred people must accomplish the tasks listed in the referral system (battle x times, nurture x pets) in order to level up and get points, if I recall correctly.

Q4. I don't believe you can get diamonds for any referral bonus.

It has a bar in the referral page. The Bar itself has Diamonds as the completion prize.

The Tasks are only visible to the one signing up aren't they?

I believe you get diamonds once you have used up all other referral bonuses. So once you have 15 (i think) points used on the three power ups, the next one will give you diamonds. Not done this myself, I think I read it somewhere....

P.S. This is what I found out when I started, well over a year ago. Things may be different now.