Referral programs often have specific time limits or conditions for links to remain active. Some expire after a certain number of days, while others stay valid as long as the platform is running. Since BMF.io rewards members for bringing new users who register and participate actively, knowing how long referral links remain valid is important for proper planning. It would be helpful to know if once a referral link is created, it stays active forever or if it becomes invalid after a period of inactivity or account changes. Are referral links on BMF.io permanent, or do they have an expiration time that members should be aware of?