Just like the title of the post says, I wonder, sometimes, I could say that I am puzzled, how these behemoths from today convinced people(small businesses)to sell on their platforms in exchange for a commission for every transaction that the end-users made. I would love to see some original samples of emails or some other form of written communication between the founders of these companies and the first sellers that decided to use these marketplaces. For me, at least, as a Software Engineer with a not negligible experience under my belt(6+ YOE), convincing some strangers(small businesses included, as they are run by strangers as well) seems something surreal. I don't know, maybe I am much too introverted to understand the ins and outs of this art(or science?) of pitching a product/service.

Just a curiosity of mine. I just want to know about these things from people with real experience in this field. Of course, opinions are also highly valued.

P.S: If this has been asked before, then I'm sorry for duplicating the question.

Thank you all in advance!