It's on my mind because I'm speaking at the UK BookCrossing UnConvention in Edinburgh on Saturday. It's also on my mind because I talked about the practice on Radio Scotland's Book Cafe a couple of weeks ago, along with enthusiastic BookCrosser and UnConvention organiser Liz Broomfield.
I was playing the odd role of devil's and angel's advocate in the discussion. After all, I wouldn't be speaking at the UnCon if I was against the whole thing, but the interviewer wanted to know: was BookCrossing a bad thing for writers? It's one more way of cutting our earnings, after all, and heaven knows there are already enough ways of doing that.

There are a few answers to this from BookCrossers. Firstly (they say), they try books they'd never otherwise consider, and expanding the readership of books can only be a good thing. Secondly, if they love your book, Crossers will often end up buying it, for themselves or as gifts. Thirdly - and here's what I like - part of the deal, with books passed round web 'Bookrings', is that you get an online review. And reviews in the regular press are almost as hard to come by as royalties from Tesco.
I confess I'm keen on it, and not just because the BookCrossers have been largely nice to me and my books. All their arguments have merit, but more than that, I like their enthusiasm. I like that they are passionate about books. I can't help feeling that as long as there are people like BookCrossers around, books won't die the death that's often foretold.
Of course, I also hope that BookCrossers love books enough to understand that there won't be as many of them around in the future - at least, books not written by Jordan - if writers can't earn a living.
But I know a lot of writers are against the whole idea. I'd love to hear some views. Then I could put on my General and Allied Writers Militant Union hat on Saturday, as well as my Kiss-Me-Quick-BookCrossers one.
And I couldn't think of an illustration for this post. Which is why I've been a chancer and just posted a picture of one of my covers, Bad Faith. Sorry.