Why use XSL variables? (1)

XSL variables can be very convenient in a lot of different circumstances:

When you have a static value that you want to use many times in your output.
For instance, you might need to output the title of a document many times in different places. If you put it in an XSL variable, and the title changes, you only need to change it in one location in your XSLT.
XSL Variables, slide 7 of 11