I have MANY ads running a promo that will expire the end of the month. I don't really want to edit every ad so I was thinking about creating a second ad and editting the line that has the promo in it. Will that slow my ads?
Hope you follow.
If you have the ad optimizer turned on in campaign settings, the ad with the highest CTR will show most often.
If the ad optimizer is off, the ads will be randomly rotated.
It's often best to keep multiple ads, as when you edit one, it isn't shown on partner sites until it's approved again, so having a 2nd ad that will keep you at full exposure is useful.