I, for one, would happily pay the price to know my money isn't subsidizing lobbying to legalize the cable-fication of the internet.
But we have no way of knowing that Verizon and Comcast aren't their backend. For all anyone knows, giving them money _is_ giving Verizon/Comcast money.
Either way, money talks - as a consumer, if I use Philly Wisper, I am explicitly saying "Net Neutrality is important enough to me to seek out businesses that promote it."