My guess is she told him she was going to play her little sex tape for Mimi, et al and then we'd just see how many of his Mormon girls wanted anything else to do with him. Or, she told him she is soooo sorry but her phone that she had recorded that on, is hopelessly lost and she is worried it will fall into the wrong hands but she is soooo sorry and sure hopes it doesn't.
It was not a financial matter, in my opinion, she made some personal threat and then tried to back up off of it, saying she was kidding and sorry. Or he busted her flat out and confronted her about slitting the tires, and following him and Mimi on dates, etc. All of that had been recent. Mimi said that she and Travis became aware that Jodi was following them, on their first date.
It was something very personal, not money, imo. Also we know she stole some of his diary pages and pages of the book he was writing, and the engagement ring. No dude would steal those things. ONLY Jodi would have stolen those things, so if he learned they were all missing, he KNEW it was her.
Or, maybe she did pull the oldest trick in the book, Travis, don't leave me, I'm pregnant.