In my imagination I know just what the accounting department of a publisher looks like. All Victorian-style tall desks, quill pens and hunched accountants scribbling away in vast, dusty tomes.
Surely it can't be any other way?
Why do I say this? Because in our up-to-the-minute, instant-electronic-transfers-of-cash, point-of-sale-information-system world, publishers pay their authors' royalties only every six months, and that can be 9 or 10 months after the cash was earned. And that's if you're lucky. Over the last few years, some publishers have worked hard to get royalties paid annually instead.
In case there's any confusion over how authors get paid, the normal process is like this. Up front they get an advance, which can range from zero (often with academic publishers) to a lot. They probably average about £2,000. Once the book starts to sell, the author's earnings from each sale (typically around 50p per book), starts to offset that advance. When the advance is paid off, then the author is paid royalties* - but royalties are paid a six month period at a time, usually three to four months after that period ends. So for July to December 2008, the author will typically be paid in April 2009.
This system was designed for laborious manual accounting. There is absolutely no justification for maintaining it with modern information flows. Rather than trying to move royalties from six monthly to annually, there is no reason why publishers couldn't move to monthly payments, perhaps 2 months behind sales. Unless, of course, the staff in publishers' accounting departments would like to move to receiving their salary every six months, four months in arrears...
* Sometimes you have to wait longer than this, as some publishers set aside some money to offset returns (books sent back by bookshops) before paying royalties.