The goals of managers (and business in general) are profit maximization, and of course upselling exists exactly for that. And if a manager decided that we need to add another upselling screen then it's more or less futile to disagree from the position of a subordinate employee. The decision has been thought of and made.
People who tend to blast their music on a loudspeaker are not exactly the kind of people who are going to accept the message.