I could be wrong, but Dana offered up the most money this season for knockouts and submissions. Logically, it seems this would motivate fighters to go in for the kill.
However.. watch this https://www.youtube.com/watch?v=u6XAPnuFjJc&feature=youtube_gdata_player
That video basically says, it has been discovered that if money is a good motivator for BASIC COGNITIVE ACTIVITIES. Anything beyond that, money becomes a horrible motivator.
I've also heard that humans are more motivated to NOT LOSE money versus WINNING money. So I don't really have a solution, but posing a different problem. Maybe Dana offering these finisher bonus was counter productive. Thoughts? 
Forgive me if that link doesn't work, I'm on my phone. If it doesn't work, go to YouTube and find the video with the title RSA Animate: the surprising truth on what motivates us.
TTT