I second that. Once a vendor becomes important enough I even stop thinking of it as a vendor and rather as a partner that you interact with as if it was part of your own organisation. I am not amused when members of my team are rude to a vendor and jeopardise a relationship that took a long time to build. Even when you pay six figures a month, you can still get preferential treatment compared to other customers in the same tier when it comes to influence over the roadmap if you actively foster the relationship.