Nielsen Bestseller Award winner: Mark Billingham

The latest Nielsen Bestseller awards revealed that you've now sold 500,000 copies of Sleepyhead, 250,000 copies of Scaredy Cat, and 250,000 copies of Buried - what does that mean to you?

The idea of those three titles selling a million copies between them seems fairly ridiculous and I'm still trying to picture how far all those books would reach if they were laid end to end. From here to the bottom of the garden? The main road? Milton Keynes? In all seriousness, you never really dare to think about how many copies a book might sell (or how few) because that way madness lies, but to know those books have reached so many readers is hugely gratifying.

At the end of the day, it's readers that writers should be thinking about rather than units, and knowing those books have found their way into the hands of so many confirms at the very least that I made the right decision in giving up the day job. Not that I've ever had what you might call a proper day job to give up, but you get my point...