Fewer people than ever are watching The Vampire Diaries. The show has recently hit series lows in the ratings for both overall viewership and in the much-coveted 18-49 demographic. So, what gives? Why are fewer people than ever before interested in watching the love triangle between human-turned-vamp Elena and the impossible attractive Salvatore brothers? We speculate below!

The numbers. How far has TVD fallen? Let’s look at the ratings for Season 5, which is wrapping up in just a few more episodes. Back in September, the Season 5 premiere was down 25 percent from the Season 4 opener, and the ratings have dropped further from there. While more than 2.5 million people watched the Season 5 premiere, giving it a 1.2 rating in the key 18-49 demo, Season 5, Episode 18 only delivered 1.66 million viewers, with a 0.7 rating in the 18-49 demo. This was the second episode in the row to mark a series low in the ratings. Season 5, Episode 19 enjoyed a modest rise — with 1.8 million viewers and a 0.8 in the 18-49 demo — but that still represents a rather sizable drop from the beginning of the season, which was already a sizable drop from the season before. Oh, dear.

The possible explanations. No one cares about vampires anymore. Many pop culture critics see the decline in TVD ratings not simply as a diminished interest in the show, but as a diminished interest in the vampire genre. Entertainment Weekly argues: “Right now? Vampires are something far worse than frightening. They’re boring.” The article points to the flop of Vampire Academy in the theaters and the decline in both True Blood and TVD viewership. This could play a factor in the ratings decline for TVD, but we’re hesitant to call it the major one. We think viewers will always have an interest in good stories, whether they have vampires in them or not.

The narrative structure can only support so many stories. A far more likely explanation, in our mind, is that people are tuning out because TVD has not been able to pull off the same narrative intensity coupled with character continuity and heartfelt development as it has in the past -- at least to the same degree. This is most likely the nature of a show that is entering its sixth season, with more than 100 episodes under its belt. That’s a long time to keep a story going -- especially one that relies on somewhat rigid structures like the coming-of-age theme and the love triangle. Arguably, Elena and her friends have already come of age. What comes next? And, right now, the love triangle is less love triangle and more love amorphous puddle.

They have lost The Originals. The risk of launching a spin-off show is that, when it includes characters from the original series, you risk losing a vital element. In other words: there’s a reason Klaus, Elijah, and Rebekah were able to successfully hold down their own show: they’re compelling characters portrayed by talented actors. The Originals’ gain was TVD’s loss. Though the Mikaelsons were never the focal point of TVD, they did add a certain pizzazz to Mystic Falls.

The importance of the Season 5 finale. Most likely, TVD’s ratings decline is the result of many factors. And, though the ratings have dropped, TVD remains one of the highest-performing shows for The CW. It already has a sixth season scheduled, and there is no talk of canceling the supernatural drama. That being said, we can’t help but think about how important these final episodes of Season 5 are, especially the Season 5 finale. A summer hiatus is a long time. Shows have to leave viewers interested enough with their season finales to ensure that they will tune back in months later. All signs point to TVD having a killer season finale that ends on a major cliffhanger. We just hope it’s enough to bring viewers back for Season 6.

Why do you think TVD  has lost viewers? Share your theories in the comments below!

The Vampire Diaries airs Thursday nights at 8 p.m. ET on The CW.

Kayti Burt is a contributing writer for Wetpaint Entertainment with a penchant for all things pop culture. Follow her on Twitter and Google+!