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I am a freelance graphic designer and very new to this field. I have a client who is starting an e-commerce commerce business. I am not working with him hourly or on flat rates. He is saying he will give me 10% of profit from my designs. Is it ok? Also I have designed a character for him. The idea of the character was his but all designing is mine. Should he share copyrights with me? If not what should be the compensation?