I recently joined The Illustration Guild group on LinkedIn, and it's been a great place full of interesting discussions on illustration. Recently someone had the chutzpah to post in the group a request for illustrations for a magazine, saying that they had no budget, but the experience would be "priceless."
As you can imagine, they did not get a favorable response from the group. A few people posted the link to this satirical Youtube video:
As I mentioned earlier on this blog, a lot of people contact illustrators without really knowing what they're asking for, or not being willing to pay at all. I found a great blog post on the topic, where the author lays out a form letter that you can send to individuals who want you to illustrate their children's book. Specifically designed to intimidate clients who haven't done their research, it contains questions such as "is this your first children's book?" and "how do you plan on publishing and marketing this book?"