Motivation eh? Hmm... I don't have one at least I don't think I do. I write because I HAVE to write, simple as. If I have a story inside me it burns until it gets out. I don't have a moment's peace. Whenever I am doing anything else it is taking me away from my keyboard. I write on the bus, the train, when I am supposed to be working, when I am waiting to see my son't teacher, when I am supposed to be making tea... any time, all the time. Recently I have taken time off writing to paint but that is only because the painting absorbs me as much as the writing does. Call it my OCD
What sparks of an idea? Absolutely anything. Death by Dreaming was sparked off by a mannequin in a shop window. The story has absolutely nothing to do with that but I am prone to extremely circuitrous thinking.
As for what motivates me to participate... well it's the fact that I am nosy, loud mouthed and opinionated... and I just love people... especially when they will talk dirty to me