Susan Kirkland: SPECulative at Graphic Design Forum Blogs
If you are invited by a big client to do work on spec, react with enthusiasm for the project, then politely suggest current projects prevent you from participating in that way. Suggest an alternative method of vying for the job; a portfolio showing of similar jobs you have completed for other clients. It shouldn’t be necessary to clarify that you will dedicate your creative energy to their project with the same verve; just not for free.