Graphic Novels are still growing!  Nielsen Bookscan reports that they grew 35 percent from 2004 to 2005, which is right about the time that libraries started to get on the bandwagon.  This article has all the stats, but also some real bad advice like reading about the genre before beginning to read the actual graphic novels.  While that is fine for some, many understand the genre already because they read comics as children.  The teens who read and love graphic novels are not worried about understanding the genre as a whole, they are just jumping right in and enjoying it.  Try it!