Referrals | Ostrom Help Center Referrals Want to know how our referral program works? See here. By Karl and 2 others 3 authors 6 articles What are Ostrom Rewards? Can my referral code expire? I forget to add my referral - can it still be applied? How do I get on the Ostrom top referrer list? Can you explain Rewards with an example? How do I enter the monthly hoodie lottery?