In the referral model, you don't manage the sales process yourself: the customer makes their purchase on the main site through the referral code or link you shared, and you earn a commission on that sale. Your earnings are transferred to your bank account on a periodic basis. In the direct sales model, you manage the process yourself: you create an order on behalf of your customer using your wallet balance, and deliver the eSIM yourself. Your earnings are the difference between the price you paid and the price you sold it for, and stay with you directly.