This won't make much sense to someone who doesn't print their own, with services like stamps.com.  Occasionally I have used "Ground Advantage" (formerly First Class) when I could use the lower rate for large envelopes considered "Flats."  Because, Ground Advantage gets a tracking number.  I don't really need certified, I just need to know it arrived, and when.  So I just pay an extra dollar or so.

I did that last week, with a form going to the state revenue department -- it wasn't even a tax return, it involved unclaimed property -- and today it was returned to me, with the name and address of the recipient pasted over with a label that told me I couldn't use Ground Advantage for a Flat.  Well, excuse me.  I promise never to do it again. 

Did anyone catch the video of our Postmaster General, covering his ears at a Congressional hearing recently because he didn't want to hear what an elected Member of Congress on the postal oversight committee was saying to him?  I don't want to mess with that guy.