Surprisingly, it helps clients understand the HTML content prototype better. They now clearly see the difference and the relationship between content and design. In general it helps me explain the content-first process better and it helps them make more sense of it.
Samantha does an excellent job of explaining how useful style tiles can be for visual design and iteration.
Samantha put together this handy one-page site to explain Style Tiles as part of her South by Southwest presentation.
Samantha gives the rundown of a hands-on use of Style Tiles.