I agree with the article but would add that a lot of times sales people are hired under the "business development" umbrella simply to not call them "sales" people - most businesses don't want to be contacted by a sales person (except when you do know that you absolutely must acquire a certain widget). At the same time, this isn't true for most startups: most startups by definition (given they do something new) don't sell existing must-have products but current nice-to-haves with a potential to become future must-haves if their transformative vision pans out.