Not much better than any other Ronda PPV. Cyborg quite literally has to ride Ronda's coat tails for any media attention, and has done so for a couple years now. This strategy only pays off for her lesser fights in Invicta where a Rousey fan who saw her tweet may tune in. The fans that Cyborg is trying to acquire with her coat tail riding were already aware of Rousey and tuning into Rousey fights, there for I doubt Cyborg moves the needle any more than someone like Sara McMann, who has just as good or better qualifications leading up to the fight in the casual mma fans eyes (olympic medal>D-league MMA org belt).
The truth is Cyborg brings extremely few of her own fans to the table because she has yet to generate much fan interest by herself in the smaller orgs she stays in. The interest she has generated lately has 100% been from her constant challenging of Rousey each time she fights. Cyborg by herself, a large woman who needs a division to herself because so few women fight at 145 and was busted for steroids and who isn't exactly turning any men on with her looks, brings very little to the table marketing-wise outside of a few fans in Brazil who had heard of her outside of the context of Ronda or Gina.