Also, just because you are offering a simple cash bribe doesn’t mean the party trying to subvert the person you are bribing is doing that and not, e.g., putting a gun to their head as a stick while also offering a cash bribe as a carrot.
Or just bribing someone else in a position to withdraw the authority that the person you bribed is using to protect you.
In fact, bribes can walk up to you without any connection to you (re: corrupt police)
That's for the discount
It's to ensure that someone in the network has pre-screened you, and that you understand the rules about how the bribe is to be paid.