Why is there a WALKING DEAD spin-off?

Answer: $$$$$. AMC have a phenomenon on their schedule, but the cash cow only produces 16 episodes a year, which they split into two batches to try and make it feel more substantial. A spin-off (sorry, "companion" series) will help keep THE WALKING DEAD universe on-air for twice as long, while benefiting from fresh characters and a different location. It also helps that this new series (codenamed COBALT) won't be following an established comic-book's lead, which will mean no spoilers and a less predictable direction. Here's what we know:

• The Walking Dead's creator, Robert Kirkman, is very involved. He's written the pilot's script with David Erickson (Sons of Anarchy), who will be the showrunner.

• It's once again executive-produced by legendary Hollywood producer Gale Anne Hurd and Dave Alpert.

• Adam Davidson (Community) is directing the pilot.

• The new series is a prequel, taking place in and around Los Angeles. It's unclear if the majority of the show will happen pre-outbreak, but my guess is we're effectively seeing another story taking place during The Walking Dead's first season—but with more time setting up the characters and this world before the dead arise.

• Cliff Curtis (Gang Related) is playing the lead; a teacher called Sean Cabrera, who has a son called Cody with his ex-wife Andrea.

• The female lead, Nancy Tomkins, a guidance counsellor who works at Sean's school, hasn't been cast yet. Anna Torv (Fringe) apparently auditioned for the role, but isn't a contender.

• Nancy's drug-addict son, Nick, is played by Frank Dillane (Harry Potter 6). Her ambitious daughter, Ashley, is played by Alycia Debnam Carey (Into the Woods).

• There are numerous supporting roles: Matt, the jock boyfriend of Ashley; Art, the principal at Sean's school; Tobias, a young boy who believes the outbreak is doomsday; and a drug-dealer called Casper.

How does that all sound to you? To me, it feels like the people behind The Walking Dead have realises the limitations of their characters and the location it takes place in, so are using the spin-off to address some growing frustrations. There's clearly more of a focus on family here, and it will be visually more enjoyable to see the City of Angels during a zombie uprising.

It'll be interesting to see what happens if AMC commit to making this series beyond a pilot. Will it have something genuinely fresh and interesting to say? Or is it just going to be more of the same, with different people and backdrops? Will viewers of The Walking Dead lap it up, or will they see it as the unnecessary sibling of their beloved franchise? Aren't people all zombie'd out?