This is exactly the conclusion of an interview of Barbara Corcoran[1] (a business-woman who has known Trump for years) back in May:

"He's probably one of the most powerful & effective salespeople I have ever met in my life"

But as she mentions, good salesman skills aren't what is expected of a President's job. It's certainly a very good asset for winning votes in the election, but not what people should want to see in a leader. In a smaller scale, it looks similar to the absolute best car dealership salesman elected mayor of his town.

https://www.youtube.com/watch?v=va5oTjuYOvc&feature=youtu.be...