It’s no problem to run your Spreadshop as a non-profit shop. Non-profit shops are interesting for non-profit associations or organizations that are not allowed to make a profit since they would otherwise lose their non-profit status. With the non-profit option, one click sets your margin to zero and you forgo profits in your Shop (Shop Settings > Prices & Promos > Shop pricing). Your retail price is thus the same as the base price. You will not receive a volume commission, nor will you be liable to share the costs of discount campaigns. You can find more information on the taxation of your shop income here.