I am planning on creating a wesbite that will give out promo code for discounts for buyers to buying stuff with bitcoin.
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shops like these that would affiliate with me for promo codes so that I can give discount promo codes to people?
Prity simple, just find best e-commerce website of your country (here in India we have flipkart, Amazon, snapdeal) then go affiliate section then u could find all the details on affiliate program of that particular ecommerce site. They usually pay 3% to 12% commission.
So you could make a website and share your affiliate link then when visitor will make a purchase then u will get your commission. Based on your commission u could pay 50% to your client