The rewards are free bet promo codes given at different stages of the marathon:
After 6 days: Earn a free bet of 273.5.
After 16 days: Earn a free bet of 683.75.
After 18 days: Earn a free bet of 1094.
After 25 days: Earn a free bet of 1641.
After 30 days: Earn a free bet of 2188.
These promo codes are credited within 24 hours after completing each milestone.