As G Felis reminded me on Facebook – Scalzi has already written about this. Beautifully.
But what about charity and/or friends and/or [insert what you think is a good reason not to take money here]? Well, what about them? I’ll note that when I approach friends about doing work for me, I typically pay them for their time. I mean, you don’t think Paul & Storm or Jonathan Coulton wrote those songs for me for free, did you? No, I paid them. Do you think Jeff Zugale did that awesome Unicorn Pegasus Kitten painting out of the kindness of his own heart, or the writers of Clash of the Geeks did it for nothing? No, everyone was paid. Why do I pay them? Because when I do work, I like to get paid, so I assume my friends who are creative people like to get paid too.
As for charity, well, if it’s the actual charity group, the organization probably has a budget, and my work falls under that. If I do the work pro bono, then I get a nifty tax deduction, which counts as compensation for my time, but a charity would be foolish to assume that I should expect that to be the entirety of my compensation. Alternately there are times when I’ll decide to do something for a charitable reason without getting paid for it, but that’s me deciding to do it, not the organization asking me to; typically the organization is surprised when I show up with money for them because they didn’t know it was coming.
As for any other reason you might think of, look: When I want to write for fun, then I do it. But when people come to me — especially people I don’t know — looking for writing, they’re asking for work. The work might have the potential to be fun, or interesting, or morally edifying or whatever, but it’s still work, and the bright line for work is this: You want work? You have to pay. Because it’s my skill and talent and expertise and time you are asking for, and they are all worth something.