From my experience working for an ISP, business is more likely to be affect ed for organisations that don't pay for Goodmail certificates. End users just see one thing - email you sent me doesn't get to my AOL account, but email that othercorp sends me does. They don't care about the technicalities of what systems AOL is using that are getting in the way, all they see is service works from x but not y. Large email providers like hotmail and AOL hold everyone else in the palms of their hands, either we play ball, or we lose business.