I recently picked up an issue of a magazine that just came out - brand new. I read and loved it and quickly emailed the editor with a query, which he accepted. And, in a matter of days I had an assignment, well two actually, I was to do a book review also, along with a 2500 word article. I was then told that they couldn't pay me, but in copies. At first I thought nothing of it, but the more I thought about it, the more I thought, "I can't keep writing for publications that don't pay." So I emailed the editor and very politely told them that I couldn't do the articles without compensation.
I don't know if this was right or not, but I know that I can't keep writing for no money. It's hard enough getting paid as a writer as it is, and nowadays nobody works for FREE!