It's partly under their control and it partly isn't.
Under their control: their image, their persona, their reputation, business sense and most importantly imo if they're a champion or not.
Out of their control: what they look like, who they know at companies that would pay them, how much push they get from the UFC
Georges had it right with a PR team and agents going out to look for opportunities FOR him. The difference being that he was a highly respected and highly dominant champion that put seats in asses. Someone like Keith Jardine (sorry Keith) is going to have a hell of a lot harder time securing a lucrative contract and some assclown like Thiago Silva is probably too busy getting arrested for something to even talk to sponsorship people.
I've thought for some time that one of the biggest issues that these fighters have been having is that they're hiring shoddy managers. From what I can tell, just about anyone and their kid brother can get some business cards printed, spit out a contract on their lap top and call themselves a "fight manager".
The problem with that model (and it happens in music and boxing as well) is that most of these guys can't market their way out of a wet paper bag.
Long post incoming.... /RANT ON.
Marketing and building a brand is actual work. It requires defining the characteristics of your product, aligning it with the correct market segments, and then banging on doors to find the right sponsors.
More importantly it requires active work with media and in the relevant communities to continue to build your brand day in and day out so that you can go to potential sponsors and say, "My guy has a fan base of XXX, they tend to be from YYY demographic, they're hardcore as heck, and I think they'd be a great fit for the image you want to project into the marketplace."
If a fighter has a half decent manager, the manager would FORCE them to do media, to hit every podcast in sight, to do interviews with the local news as often as possible as well as make public appearances and engagements to make sure that they are being remembered as more than Anonymous_fighter_001.
The problem with the pre-Reebok model is that it allowed WAY too many "managers" to sit on their asses and coast on the "Oh, he's on fight night with XXX anticipated viewers" and then just negotiate for a check. Now, with the gravy train gone managers are actually going to have to WORK for a living and that's why you're seeing fighters re-assess their relationships with the fighters.
Here's something that people don't realize, but the Women actually have mastered this. Since the women's divisions didn't even EXIST 3 years ago, the women got a ton of hard knock lessons on how to guerrilla market themselves. Look at early interviews with fighters like Tate, Carmouche, Kaufman and Rousey and they would talk about banging on doors, selling T-shirts out of their cars, engaging frequently on Twitter or AMA's, etc. Flyers, walking the pavement to sell tickets... they were willing to do anything and everything just to get butts in seats and people paying attention.
Is it any wonder that Miesha Tate, the #1 contender in 135 has MORE twitter followers than many of the actual Men's Champions? Hell, she had more followers in Strikeforce than some of the current Male Champions. Think about that... these guys had ALL the advantages of TV, mainstream press, UFC marketing muscle, and a bunch of girls working in obscurity were building higher profiles than them.
Yes, it's a new world and athletic pay sucks in the UFC without branded ring apparel but a portion of the blame also has to go on the fighters. When champions have to be dragged to interviews, when fighters say that they won't do interviews outside of the contract required time, and when fighters won't engage in social media can we really place the blame fully on the UFC and the UFC marketing machine?
Think about this, let's say you're the UFC and you've got a fixed budget but 500+ fighters on the roster. How much are you REALLY going to spend to promote a fighter who doesn't want to promote themselves? Are you going to go out of your way to help the guy that doesn't want to step up to the plate? Or are you going to put your dollars to people that are willing to put their nose to the grindstone, make no excuses, do the promotion and STILL put in the time to train and fight?
Free rides are great when they last, but when the gravy train shuts down that's when you find out who's really willing to put in the work and who thinks they're too good to promote themselves.
If half of these fighters used their brains, they would start calling up the women fighters that they know and ask for lessons.