The short answer to this question is that there technically is no limit. That being said, users can only earn 100 coins for their own personal achievements in any app. Because any of their direct referrals can earn up to 100 coins themselves in a given app, the user that made that referal can earn themselves up to 50 coins for the achievements in-app of the referred person. For the referred person of a user’s referral, they can earn up to 25 coins, then 12.5, etc. etc. The number of people a user can refer and earn coins off of is NOT limited whatsoever. If a user refers 10 people and they all refer 10 people themselves, the original user would earn up to 500 coins in an app from their direct referrals, and up to 2500 coins from the indirect referrals. There is no cap to these width of these referral trees. They award WildFire Coins up to 6 generations deep beyond the original user. This holds true for the 10, 5, 2.5, 1.25, 0.625, or 0.3125 coins they would get for a referral, based on how far down the referred person is relative to the person higher up in the referral tree. One person can earn coins in this manner in as many WildFire enabled apps as they like, meaning that a user earns the 10 coin referral reward from the WildFire Bank for each app they successfully refer someone to, even if it is the same person and that person is above or below them in referral trees in other apps.