During the past eight years, one in which books became more difficult to sell, the nasty couldn't hide. They had to be out there for the whole selling process. Books have to be pushed from pre-publication into forever. Otherwise they fall down the Amazon ranking hole.
Informally, I have observed that the nasty might start strong in the Amazon ranking. Usually they have the infrastructure to prop book sales up. Soon enough, the numbers begin sliding, then plunging downward. They have alienated those who could keep the promotional show going. And those they have watch with glee at the free-fall.
The lesson here is this: When things get tough, as in selling books, emotional intelligence becomes more important. Those other kinds of resources such as money or previous success help less. So, authors who want to be on top of book sales and stay there should be nice. Not nasty.