Now this is a very simple question, though I believe the answer isn’t that simple. Because the show is so popular with almost everybody, even people that never watch horror.
If The Walking Dead (TWD) would be popular with a certain group of people, it would be easy to find a reason. These people will have one shared interest and TWD would mainly be about that subject. For example: If the show were only to show a few bad-asses shooting shotguns, the group of people interested in the show would be very limited.
So, we can safely state that people need to share an interest, now for the TWD people can have several interests. There are zombie fans, woman that are into Norman Reedus, horror fans, survival fans, etc. This makes for a large group of people that have interests that correspond with what’s in the show.
But… Just an interest in one or two subjects on a show won’t keep people watching. At least not masses of people, making it one of the biggest shows in the world. So what does make so many people watch a show? Become obsessed with it?
Identification. People need to relate to characters in the show and live their pain, happiness and other emotions. The story and characters in TWD are very well developed and change as the show continuous This makes people live the story and feel with the characters as they change. This, combined with massive plot twists and the realization that even the most likable characters can die, creates amazing cliff hangers.
It’s the diversity in subjects and characters, worked and provided in such great detail, that makes everybody find someone they can relate to and have several interests that translate into the show. TWD mixes several genres and subjects together and throws a zombie sauce over it to create a common enemy and introduce fear in the lives of characters people can relate to.
Besides people to relate to, there are people to look up to. Norman Reedus, as massive anti-hero. The silent underdog that finds his calling during an apocalypse. Smoking, drinking, killing zombies while holding a baby in one hand. Come on, how can people not look up to that and not want to see everything that character surprises us with? This doesn’t just go for Reedus. Remember now Dale died? Or how unexpected T-Dog was ripped from the show? It’s characters like these that people look up to and want to relate to.
At last, the show is full of common enemies. Take the governor for example, a well made character that oozes evil for you to see, but seemingly nice to the characters we relate to. This common kind of enemy makes people feel like they’re part of the show. It makes you hate someone and relate to the people suffering by what he does to them. You then live and love every small victory the characters have on this common enemy. This of course is only possible because of the great directors and creators, that know HOW to build a character.
This is just my take on why TWD is such a success. I’m sure there are many other reasons, or very specific reasons for you to like TWD. I’d love to hear those from you!