Ah, I also found an app others may find useful. It's called
My Data Manager and it indicated that 1MobileMarket and Enhanced Email had downloaded 25% of my Kindle usage this morning so since I don't really use either app, I uninstalled them.
The app shows the usage for every app on your Kindle for the day, month,plan, etc.
EDIT: The app has 4 pages. You need to swipe to get to the second page which lists the apps and how much bandwidth each uses. (Took a couple of days for me to discover that - I'm not the sharpest knife in the drawer.)