I know this post is dated, but I have a question as I am experiencing the same issue. I've read through this whole post and keep seeing "if it was previously installed on the device".

I recently purchased me a new phone and gave my older phone to my friend. The old phone was factory reset before I gave it to him. I invited him to play Raid...he has never played before. He is now Lvl 19 and I haven't gotten the first reward, nor is he even on the list of refereed friends. So is it because RAID was previously installed on that device, (even though it was factory reset and now belongs to someone else now)... that the referral system is not counting him as a refereed friend? If so, that's pretty lousy with the amount of recycled and used phones being sold on Amazon and Ebay.

Please...any response woul dbe greatly appreciated.

So to have the referral work, it has to be a brand new install on a new phone/tablet?  Does this mean I can not give a referral to my wife if she wants to play on our shared tablet? And does the email you send it to have to be the one the app store is registered under?   We share a tablet and I don't want to waste the start up if that is the case.

Still, no answer?

It's funny, 

This is the first time I have actually looked into this problem (I haven't bothered with tickets) and it explains a lot. I had assumed that the same IP was the issue and it looks like that was right. However, I looked into it because my referral link to my daughter didn't work on the factory reset old phone of mine. This is crap as it means that even when it is a genuinely new user iltge links don't work. 

Same problem here. I had assumed that the same IP address was an issue however, my daughter has my old phone that was factory reset and the link didn't work there either. 

Wake up Platinum, you are not going to miss out on money from people having multiple accounts.

Same issue sent two referrals about the same time i started mine. Accounts are all about the same level and nothing.

My account id: 

um62487094 | 60953526

Referral accounts

Level 44

um62690665 | 61151512

Level 46

um62819851 | 61277501

No gifts received at all.