Using Impression Share (IS) as a metric at the current campaign level may not be as useful as we want it to be especially for campaigns with volumes of adgroups. I have tried to confirm it from Google reps if they are using some version of IS at the adgroup level and luckily got a “read between the lines” reply that they might be using one. Better yet one rep I’m working with dropped a hint that they may release the IS metric at the adgroup level.

This may sound impressive and will likely help the metric provide granular insight on adgroup performance.

Will an adgroup level IS be significantly helpful to you?