So, you want to get advertising with money that you write off for tax purposes. In many world states that would constitute tax fraud. And have the reputation of those FOSS developers benefit you, to boot. I'm sorry, that's a bit much from a small mind such as mine.
In the US, pretty much any expense that a business makes as part of running a business is deductible. You do not have to donate to a 501(c)(3) to get a tax break.
