Does anyone use git-notes?

I would like to write a post on how to use them, but I'm a bit
confused as to how people actually use them on a day to day basis.  I
appears to me in trying to work out a flow for them that the lack of
an ability to merge them makes them very difficult to use for anything
practical.  Can someone share with me how they use them and what the
cycle is?

Thanks,
Scott