I enjoy using metaphors in my writing, it is like putting big things in small packages :D
Seriously though, it is very useful for taking complicated subjects and boiling them down to a few words which is vital in today's short attention span culture. Additionally it has the added benefit of using the "anchoring" effect, which is an educational strategy that increases retention by building on existing associations.
that's funny you mention that @ericathurblair because I am focusing on education and that makes me feel good that I have used a technique that is recognizable
Study anchoring if you already haven't, it is an amazing tool, and it makes what you teach last.