If there was ever a reason not to have Daniel Cormier's next title fight come against anyone not named Jon Jones, the UFC 192 buyrate is Exhibit A, B, and C. According to Dave Meltzer's Wrestling Observer Newsletter (subscription only), it will "finish in the ballpark of 250,000 buys," making it the 2nd worst selling light heavyweight title fight in the TUF era, as well as the 3rd lowest selling PPV of 2015 (only ahead of both UFC 186 and 191 - both Demetrious Johnson title fights).
Cormier defeated Alexander Gustafsson by split decision in an immensely entertaining main event, which saw the current champion nearly knocked out in the end of a dramatic 3rd round before surviving and seeing through the fight on points. The day before fight night, the card lost its co-main event of Johny Hendricks vs. Tyron Woodley, which promoted Rashad Evans vs. Ryan Bader to co-main status.
As far as Cormier is concerned, this is his 3rd PPV main event in as many fights. Jones vs. Cormier at UFC 182 pulled in a reported 800,000 buys, Cormier vs. Anthony Johnson (after Jones was stripped of his title) did an estimated 375,000 buys with the footnote that Weidman vs. Belfort served as co-main, and now the Gustafsson fight has disappointed considerably. The only LHW title fight to have performed worse in the past 10 years is UFC 54, when Chuck Liddell vs. Jeremy Horn had pulled in 150,000 buys.
Another conclusion you can probably make is that the UFC has twice put Gustafsson in title fights, and twice it's not performed particularly well on PPV. It turns out that "Look how tall he is!" wasn't an effective marketing tool, and the UFC literally did that both times. Gustafsson may have done extremely well vs. Cormier and Jones, but the lack of PPV buys each time out will certainly hurt his cause for a 3rd title shot.
On that note, you can pretty much jot down Cormier vs. Jones II as the next step for the UFC's light heavyweight division.