Daniel Spreadbury has been the Senior Product Manager of Sibelius Music Notation Software since 1999. His personal blog, SibeliusBlog, is "intended to provide insights into the world’s favourite music notation software, from the unique perspective of its Senior Product Manager. You’ll find hints and tips about how to make the most of the product, and interesting stories about how Sibelius is being used in a variety of contexts for all sorts of exciting projects."
That being said, I've wanted to know how to put watermarks on sample copies of my music for a while now. Here's the answer in Sibelius 6. I'm sure the same technique works in the new Sibelius 7. This video comes from Daniel's Vimeo account. Follow @dspreadsbury on Twitter to keep up to date with Daniel's Sibelius news.
Creating a watermark in Sibelius 6 from Daniel Spreadbury on Vimeo.