This is just as important service as building the product itself. And what the article describes as sales anxiety can be an asset. Introverts are more likely to be in a position of listening and not just pushing the product to do hard sales.
The book “To sell is human” really changed my perspective, as the author makes the point that the best sales people primarily want to serve others, not just trick people into buying something they don’t need. Good sales is about communicating and matching up needs to value in an honest fashion. Not “ABC”