Ostrom Rewards is the place where all bonuses from Referrals are collected.
When you receive a bonus, it appears in your Rewards and you can choose how to use it. You can apply part of it or the full amount to your next invoice, or you can redeem it for a voucher in the Ostrom Store.
Each successful referral gives you 50 € to reduce your next invoice or 100 € to spend in the Ostrom Store.