'Supernatural' didn't last 15 years on 'brotherly love' or even Dean and Cas chemistry, here’s why it worked
According to the creator Eric Kripke, EP Robert Singer, and writer and EP Andrew Dabb in the TV special 'Supernatural: The Long Road Home', the reason for the longevity of the show is the "brotherly bond" between Sam and Dean. For some, especially the young LGBTQ Tumblr fandom who championed Destiel, it was the chemistry between Dean and Cas -- the boy and the angel who would always watch over him. Neither, however, is the actual reason why the show survived so long.
Instead, the reason why the show survived this long exists outside the show itself – in all the "extra-curricular'" activities that the actors and crew got up to. The first Creation Entertainment convention for Supernatural happened in 2006. Before that, from Season 1 itself, the season-end "bloopers gag reel" was established as a thing.
In 2011, Misha Collins began the GISHWHES -- The Greatest International Scavenger Hunt the World Has Ever Seen, to encourage intense participation and investment of emotion, time, and money from the Supernatural fandom. Even people who had never watched the show got drawn into the GISHWHES craziness (it holds the record for the "largest media scavenger hunt") and later drawn into the "SPN family" as a result.
Collins, later followed by Ackles and Padalecki, frequently engaged with fans, to use the SPN platform for measurable good. Fans participating in charity drives organized by the cast not only got to interact with the stars but also had a sense of achievement about being a force for good, collectively, that they would never be on an individual level.
The Creation Entertainment's Supernatural conventions are not especially ground-breaking in any way either and very cynically, they are money-grabs playing on fans' desire to have access to the cast -- to have a bit of tinsel town magic rubbing off. But what was so special about the SPN con circuit was its consistent regularity and the number of cities it hit -- at one point even cities in Europe. This was not a once-a-year commitment. It required the cast and crew to fly frequently, be gracious, and meet fans even when they are dead on their feet after shoots. Jensen Ackles, Jared Padelecki, Misha Collins of course have been the stars of the cons, but people like Richard Speight jr and Rob Benedict have stayed in the con circuit for years -- even when they weren't on the show for large stretches of time. Minor but beloved cast members keep returning to interact with the regulars of the show on the con circuit even after they have been killed off on the show.
In some ways because of all this traveling and working together, the cast and the extended circle of guest stars have become family – this is authentically reflected in the way they interact with each other at cons. The fans attending so many conventions, running repeatedly into each other and the stars, have also become a part of that extended family.
But none of that would matter if there didn't exist hours upon hours of footage and photo-op pictures from these cons, along with SPN-connected charity drive videos, gag reels and pranks on-set, which in turn has amplified and expanded the spectacle of "authentic" friendships and bonds between the cast and crew. It has reached those who don't or can't attend cons or participate in scavenger hunts but receive these off-set interactions in the wilds of Youtube, Tumblr posts, and Twitter.
This, in turn, has expanded and deepened the feeling of 'authentic access' to the stars and who they actually are -- which is a rarity in show biz. It ended up connecting millions of people around the world who found friendship, solace, support (in actual real-life tragedies), and sometimes even true-life romance.
The cast itself has worked hard at it, grinding away at giving that access and making fans feel that they are genuine and relatable. Jared Padelecki has opened up about his depression and has supported charities related to it. Misha Collins has been a strong advocate for LGBTQ rights, playing off the popularity of Destiel. As the years went on and the quality of the writing dropped and the actors began dialing in their performances – this grind on the con circuit, social media and SPN events are what saved the show.
What the show's episodes were portraying, what the seasons' story arcs were, the performances... they all stopped mattering a long time ago. They were just an excuse to meet "family" again. Audiences tuned in to see reflections of the authentic interactions they saw off-set. It was a case of the blooper reel taking over the actual show. And incredibly, this gave the 'little show that could' the numbers it needed to keep going for 15 years.
'Supernatural' aired its finale episode on November 19 on The CW.