Google announced on Twitter and Google+ yesterday that they added version history to their ad platform so you can compare the performance of an ad before and after you make changes to them.
Google wrote “version history lets you see previous versions of your ads after they’ve been edited–and how they performed. Check it out by clicking the pencil icon next to an ad in the new AdWords experience.”
This help document explains:
Here is a screen shot of how it looks:
Ginny Marvin has an additional screen shot on Search Engine Land.
