The difference is actually just the currency. At the "real" sales talk, money ends up flowing. But even in other situations, decisions have a price:
The colleague, who agrees to assist you with your project, pays with time. And a customer who is supposed to agree to a change, for example in the execution of his construction project, pays with risk, uncertainty, and in the end perhaps even with the danger of getting in trouble. And these "currencies" often weigh much more heavily.
However, the mechanisms of the "non-monetary sales talk" are exactly the same as with genuine sales. In order to convince the "customer", you must understand him. You must ask questions in order to understand their situation, their attitude and their decision-making mechanisms. This results in the arguments and strategies that are relevant and effective for this conversational partner. You should understand how the human psyche works and how you can access this knowledge. And in the end, you should be able to come to a binding conclusion. A salesperson learns all that in good sales seminars. Whereas all the others often have a very difficult time with that.
Many of these "non-sellers" torment their interlocutors with argumentation battles. They try to convince them without trying to understand them. Others even avoid such situations and decide from the beginning that a conversation makes no sense. As a result necessary changes and improvements are blocked.
I know that many people have prejudices about selling. But in the end, we all do it, all the time. And that is why I recommend learning how to sell (to convince others) to anyone who is ever dealing with other people professionally. Then life would be a bit easier for all of us.