#4 They maintain an independent eel to its presentation
NXT's success is less about pageantry and more about execution. There is very little illumination except in the key areas, and the mats outside the ring, the ring canvas, and the railings around the ringside area are all black.
It is a clear and simple presentation that any fans can see the lighting is focused on the center of the ring, and everything outside the ring is dim and dark.
The reason is simple: all the focus is on what happens between the ropes. When fans watch Raw or Smackdown they of course associate the colors of red and blue with the respective brands.
However there is a lot of focus on the thousands of people in attendance. NXT never needs to dress up and be anything more than exciting wrestling that isn't classified as sports entertainment.