well, in a way, the Bud Light boycott has cost them a lot of sales and they've quickly tried to turn around their marketing effort. So it does cause the company to re-think how they market to their customers. As consumers, what you buy supports those companies and what they promote.
Similarly, many millennials buy products from companies based on what philanthropic efforts they support. That is a means of showing support for one company and choosing not to buy a competing product from another company.