Banner ads - Pause the banner ads onStop() and Resume onStart() is advisable

I want to know if it is advisable to Pause the banner ads when android app screen is partially invisible when user OFF the screen and onStop() is called ??
and Resume the ads when screen is ON and onStart is called?

does this make any differences for statistics or revenue??

does not matter i think.

ADMOB does this already when screen is off.