http://www.theguardian.com/books/2013/oct/11/philip-hensher-author-refuses-to-work-for-free?CMP=twt_gu

Don't always agree with Hensher, but I do on this one.

Yes, so do I.

Hard to disagree with the idea of asking for money for providing value.

We all do a sum about what the gig is worth to us in terms of money/publicity/career-advancement/supporting-a-good-cause/fun, and what it'll cost us in time and work.

Sometimes the result of the sum is Yes, sometimes it's No.

Our market value is as much about what people will pay, as what we feel we need and deserve.

But the other side of the offer-of-work really shouldn't grumble - and certainly not in public - about it, if the writer decides that what they offer isn't enough for what it'll cost the writer.