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Do not listen to the advice of those who are not where you want to be. Do not listen to those who have not tried to do what you are doing yet tell you it cannot be done. Since they have not been where you want to go, their advice will be dead wrong for you. Take advice only from photographers or business-people who are where you want to be.
Also, be very careful of the company you keep. Stay away from people who have a negative attitude and people who keep telling you that you cannot do this or you cannot do that. Instead, spend time with positive people who believe in you, listen to your ideas, and help you reach your goals. If you cannot find such people, stay by yourself and work on your marketing, which is better than listening to negative feedback that denigrates what you are trying to accomplish.