I think Robbie Coltrane hit the nail right on the head

Ive hired out DVD's of Cracker from lovefilm.com before, and when i hired out the one off 2006 episode of Cracker, there were special features on there. They had interviews with the author of the story, and with a few of the shows stars.

When Robbie Coltrane was being interviewed, he tackled the query of "why did Cracker become so popular?", and i think he hit the nail right on the head. I cant remember exactly what he said, but he said something like this.....

"I agree that Cracker is not the only television series to ever be centred around violent crime and murder, nor was it the first, many other tv series have become popular in the past for this, such as Murder She Wrote, Inspector Morse, Poiroit, Sherlock Holmes novels, so Cracker isnt original there at all. But however, compared to all those other novels and TV series, Cracker is original for something, and i think its that that has made it so popular and fascinating.

Cracker does not focus around on Who is doing the killings?, which all those others do, no. You usually see who is doing the killings the very second they take place, but Cracker actually focus's on Why are they doing the killings??, what is possibly driving them to do this?. Cause nobody just wakes up in the morning one day and goes oooh im bored, what shall i do today?, i know, ill go out and just murder people, there's always a reason and motive for them to do it, and ones that make sense to them, and thats what the series focus's on in each episode".