He used his experience in media/showbiz to exploit the media to give him free PR all the time, whereas the other politicians had to 'work for it'.
It's like the Kardashians, they actively make an effort to be in the news for something, to maintain top of mind awareness...of their degeneracy.
He also said things that were plain interesting and outrageous to hear and see. Similar to slowing down for a train crash. No secret about that and really anyone could have quite easily reverse engineered and done the same. His big skill is more having, for lack of a better way to put it, 'balls' as well as no problem with the blowback or downside of his actions. That is the secret sauce with Trump. In a nutshell the other candidates, by comparison, were boring.
i think trump's win had a lot less to do with trump himself than other factors.
It's impossible to prove a contra positive so we'll never know if it was Comey, or the Russians or what that put him over the top. But, Trump did get himself within striking distance. So, I give him credit(?) for the birther movement, and Mexican rapists, and no puppet. Because those are the things that energized his base to the point where he could win with a little help from his friends.