Your customers have endless choices. Do something that elevates your business above your competition: support causes your customers care about. Send a clear message that you are willing to give, what you can, to help improve the community.
You don't have to be rich to give. Give a "small gift", a donations of $1, $5, $10, etc. based on how much customers buy from you. You control the promotion. They buy, you give. They pick the cause, you get the credit. You help the community, they help you. Everyone wins!