Good-Person
Captain Junkie
There is no benefit that comes to a customer for just sponsoring a business without being in partnership with that business.
It is only when they have a kind of partnership with that business that sponsoring that business will bring a form of dividends to them when the business is being profitable.
Well, apart from sponsorship, there are limited options left for the customer that may help them improve or promote your business. They are left with the option to refer people to your business. I think this is the only thing they could do.