[traevesty]

You'd donate to a business for the same reason you'd donate to an individual: to give resources to a cause that you support and to incentivize a direction of work.

You might be surprised to learn that the business world already has tons of donation buttons and trust networks. For accounting reasons they're often called contracts.

[apalmer]

or you could just buy some of what they are selling... which is really the point, the public attention and goodwill created by giving this away, leads to sales and greater revenue than would be received if they just put a donate button up.

[blackjack48]

Or crowdfunding.